{"id":1721,"date":"2019-06-11T12:00:43","date_gmt":"2019-06-11T03:00:43","guid":{"rendered":"https:\/\/www.bold.ne.jp\/engineer-club\/?p=1721"},"modified":"2025-10-06T17:42:33","modified_gmt":"2025-10-06T08:42:33","slug":"java-date","status":"publish","type":"post","link":"https:\/\/www.bold.ne.jp\/engineer-club\/java-date","title":{"rendered":"Java\u306eDate\u3068\u306f\uff1f\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3092\u8868\u73fe\u3059\u308b\u30af\u30e9\u30b9\u300cDate\u300d\u3092\u89e3\u8aac"},"content":{"rendered":"<p><strong>Java\u306ejava.util.Date\u306f\u3001\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3092\u8868\u73fe\u3057\u3066\u3044\u308b\u30af\u30e9\u30b9\u3067\u3059\u3002\u3053\u3053\u3067\u8a00\u3046\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3068\u306f\u3001\u4f55\u5e74\u4f55\u6708\u4f55\u65e5\u30fb\u4f55\u6642\u4f55\u5206\u4f55\u79d2\u30fb\u4f55\u30df\u30ea\u79d2\u3068\u3044\u3046\u7279\u5b9a\u306e\u4e00\u77ac\u3001\u305d\u306e\u65e5\u6642\u306e\u3053\u3068\u3067\u3059\u3002<\/strong><\/p>\n<p>\u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u306f\u5168\u3066\u3092\u6570\u5b57\u3067\u6271\u3044\u307e\u3059\u304c\u3001\u65e5\u6642\u3082\u4f8b\u5916\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u304c\u65e5\u6642\u3092\u8868\u3059\u6642\u306f\u3001\u7279\u5b9a\u65e5\u6642\u304b\u3089\u306e\u5dee\u5206\u3001\u3064\u307e\u308a\u7d4c\u904e\u6642\u9593\u3067\u8868\u3057\u307e\u3059\u3002\u3053\u306e\u8003\u3048\u65b9\u306e\u6b63\u3057\u3044\u7406\u89e3\u304c\u3001<span>Date<\/span>\u3092\u4f7f\u3044\u3053\u306a\u3059\u30ab\u30ae\u306a\u306e\u3067\u3059\u3002<\/p>\n<p>\u5b9f\u306f<span>Date<\/span>\u306f\u3001<span>Java<\/span>\u3067\u65e5\u6642\u3092\u6271\u3046\u306b\u306f\u3082\u3046\u53e4\u3044\u65b9\u6cd5\u3067\u3059\u3002<span>Java 12<\/span>\u3068\u306a\u3063\u305f\u4eca\u3067\u306f\u3001<span>Java 8<\/span>\u3067\u8ffd\u52a0\u3055\u308c\u305f<span>Date and Time API<\/span>\u306e\u30af\u30e9\u30b9\u304c\u6a19\u6e96\u3067\u3059\u3002\u3067\u3082\u3001<span>Date<\/span>\u306f\u3053\u308c\u304b\u3089\u3082\u3042\u308a\u7d9a\u3051\u307e\u3059\u3057\u3001\u4f7f\u3044\u65b9\u3092\u77e5\u308b\u3053\u3068\u306f\u5927\u5207\u3067\u3059\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001<span>Java<\/span>\u3067\u65e5\u6642\u3092\u8868\u3059<span>Date<\/span>\u306b\u3064\u3044\u3066\u3001\u521d\u5fc3\u8005\u5411\u3051\u306b\u8aac\u660e\u3057\u307e\u3059\u3002<span>Date<\/span>\u3092\u6271\u3046\u4e0a\u3067\u5fc5\u8981\u306a\u8003\u3048\u65b9\u3084\u4f7f\u3044\u65b9\u3001\u5b9f\u52d9\u3067<span>Date<\/span>\u3092\u4f7f\u3046\u306a\u3089\u305c\u3072\u62bc\u3055\u3048\u3066\u304a\u304d\u305f\u3044\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u4e0a\u306e\u30ce\u30a6\u30cf\u30a6\u3082\u6e80\u8f09\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u203b\u3053\u306e\u8a18\u4e8b\u306e\u30b5\u30f3\u30d7\u30eb\u306f\u3001<span>Java 12<\/span>\u306e\u74b0\u5883\u3067\u52d5\u4f5c\u78ba\u8a8d\u3057\u3066\u3044\u307e\u3059<\/p>\n<div id=\"toc_container\" class=\"no_bullets\"><p class=\"toc_title\">\u76ee\u6b21<\/p><ul class=\"toc_list\"><li><a href=\"#JavaDate\">\uff11\uff0e\u3010Java\u3011Date\u3068\u306f\u305d\u3082\u305d\u3082\u30ca\u30cb\u30e2\u30ce\u304b<\/a><ul><li><a href=\"#-Date\">\uff11-\uff11\uff0eDate\u306f\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3092\u8868\u3059\u3082\u306e<\/a><\/li><li><a href=\"#-Date19700101_000000GMT\">\uff11-\uff12\uff0e\u3010\u91cd\u8981\u3011Date\u304c\u6301\u3064\u306e\u306f1970\/01\/01 00:00:00(GMT)\u304b\u3089\u306e\u7d4c\u904e\u30df\u30ea\u79d2<\/a><\/li><li><a href=\"#i\">\uff11-\uff13\uff0e\u57fa\u6e96\u65e5\u6642\u3088\u308a\u4ee5\u524d\u306f\u30de\u30a4\u30ca\u30b9\u306e\u7d4c\u904e\u30df\u30ea\u79d2\u3067\u8868\u73fe\u3059\u308b<\/a><\/li><li><a href=\"#-Date-2\">\uff11-\uff14\uff0eDate\u305d\u306e\u3082\u306e\u306b\u306f\u5e74\u6708\u65e5\u3084\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306e\u6982\u5ff5\u306f\u306a\u3044<\/a><\/li><li><a href=\"#-Date-3\">\uff11-\uff15\uff0eDate\u304c\u6301\u3064\u7d4c\u904e\u30df\u30ea\u79d2\u306f\u5909\u66f4\u3067\u304d\u306a\u3044<\/a><\/li><\/ul><\/li><li><a href=\"#JavaDate-2\">\uff12\uff0e\u3010Java\u3011Date\u306e\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9<\/a><ul><li><a href=\"#-Date-4\">\uff12-\uff11\uff0eDate\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u4f5c\u308a\u65b9<\/a><\/li><li><a href=\"#i-2\">\uff12-\uff12\uff0e\u7d4c\u904e\u30df\u30ea\u79d2\u306e\u53d6\u5f97<\/a><\/li><li><a href=\"#-Date-5\">\uff12-\uff13\uff0eDate\u540c\u58eb\u306e\u6bd4\u8f03<\/a><\/li><\/ul><\/li><li><a href=\"#JavaDate-3\">\uff13\uff0e\u3010Java\u3011Date\u306e\u3044\u308d\u3044\u308d\u306a\u4f7f\u3044\u65b9<\/a><ul><li><a href=\"#i-3\">\uff13-\uff11\uff0e\u30ed\u30b0\u3078\u306e\u65e5\u6642\u306e\u8ffd\u52a0<\/a><\/li><li><a href=\"#i-4\">\uff13-\uff12\uff0e\u51e6\u7406\u6642\u9593\u306e\u8a08\u6e2c<\/a><\/li><li><a href=\"#i-5\">\uff13-\uff13\uff0e\u7279\u5b9a\u671f\u9593\u306e\u52a0\u7b97\u30fb\u6e1b\u7b97<\/a><\/li><li><a href=\"#-DateInstant\">\uff13-\uff14\uff0e\u3010\u53c2\u8003\u3011Date\u304b\u3089Instant\u3092\u53d6\u5f97\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#CalendarSimpleDateFormat\">\uff14\uff0eCalendar\/SimpleDateFormat\u3068\u306e\u9023\u643a<\/a><ul><li><a href=\"#-DateCalendarCalendarDate\">\uff14-\uff11\uff0e\u3010\u91cd\u8981\u3011Date\u3092Calendar\u306b\u3059\u308b\/Calendar\u3092Date\u306b\u3059\u308b<\/a><\/li><li><a href=\"#-SimpleDateFormatDate\">\uff14-\uff12\uff0e\u3010\u91cd\u8981\u3011SimpleDateFormat\u3067\u3001Date\u3092\u6587\u5b57\u5217\u3068\u3057\u3001\u89e3\u6790\u3092\u3059\u308b<\/a><\/li><li><a href=\"#-Date-6\">\uff14-\uff13\uff0eDate\u304b\u3089\u5e74\u6708\u65e5\u30fb\u6642\u523b\u30fb\u66dc\u65e5\u306a\u3069\u3092\u62bd\u51fa\u3059\u308b<\/a><\/li><li><a href=\"#-Date-7\">\uff14-\uff14\uff0eDate\u304b\u3089\u306e\u6708\u672b\u6708\u521d\u3092\u8a08\u7b97\u3059\u308b<\/a><\/li><li><a href=\"#-0Date\">\uff14-\uff15\uff0e\u30b8\u30e3\u30b9\u30c80\u5206\u306a\u3069\u306b\u65e5\u6642\u3092\u5207\u308a\u6368\u3066\u30fb\u5207\u308a\u4e0a\u3052\u3057\u305fDate\u3092\u4f5c\u308b<\/a><\/li><li><a href=\"#i-6\">\uff14-\uff16\uff0e\u3010\u91cd\u8981\u3011\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u610f\u8b58\u3057\u305f\u51e6\u7406\u3092\u3059\u308b<\/a><\/li><\/ul><\/li><li><a href=\"#Date_and_Time_API\">\uff15\uff0e\u3010\u53c2\u8003\u3011Date and Time API\u306e\u7c21\u5358\u306a\u7d39\u4ecb<\/a><ul><li><a href=\"#-DateCalendar\">\uff15-\uff11\uff0eDate\/Calendar\u3057\u304b\u306a\u3044\u3053\u3068\u306e\u554f\u984c\u70b9<\/a><\/li><li><a href=\"#i-7\">\uff15-\uff12\uff0e\u65e5\u6642\u306e\u7a2e\u985e\u304c\u30af\u30e9\u30b9\u306b\u306a\u3063\u3066\u660e\u78ba\u306b!!<\/a><\/li><li><a href=\"#i-8\">\uff15-\uff13\uff0e\u65e5\u6642\u7528\u306e\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u30fb\u89e3\u6790\u7528\u30af\u30e9\u30b9\u304c\u65b0\u3057\u304f\u3067\u304d\u305f<\/a><\/li><li><a href=\"#i-9\">\uff15-\uff14\uff0e\u65e5\u6642\u306e\u7cbe\u5ea6\u304c\u30ca\u30ce\u79d2\u5358\u4f4d\u306b\u306a\u3063\u305f<\/a><\/li><\/ul><\/li><li><a href=\"#i-10\">\uff16\uff0e\u307e\u3068\u3081<\/a><\/li><\/ul><\/div>\n<h2><span id=\"JavaDate\">\uff11\uff0e\u3010Java\u3011Date\u3068\u306f\u305d\u3082\u305d\u3082\u30ca\u30cb\u30e2\u30ce\u304b<\/span><\/h2>\n<p>\u3067\u306f\u3001\u307e\u305a\u306f<span>Date<\/span>\u306e\u8003\u3048\u65b9\u3092\u5b66\u3073\u307e\u3057\u3087\u3046\u3002<span>Date<\/span>\u306e\u4f7f\u3044\u65b9\u3092\u3059\u3050\u306b\u3067\u3082\u304a\u4f1d\u3048\u3057\u305f\u3044\u306e\u3067\u3059\u304c\u3001<span>Date<\/span>\u306e\u8003\u3048\u65b9\u304c\u7406\u89e3\u3067\u304d\u3066\u3044\u306a\u3044\u3068\u3001\u306a\u305c\u305d\u306e\u3088\u3046\u306a\u4f7f\u3044\u65b9\u306b\u306a\u308b\u306e\u304b\u3001\u3044\u3056\u4f7f\u3046\u6642\u306b\u6df7\u4e71\u3057\u3066\u3057\u307e\u3046\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u3002<\/p>\n<p>\u3067\u3059\u304b\u3089\u3001\u5c11\u3005\u9000\u5c48\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u304c\u3001<span>Date<\/span>\u3068\u306f\u3069\u3046\u3044\u3046\u3082\u306e\u306a\u306e\u304b\u306e\u8aac\u660e\u306b\u3057\u3070\u3089\u304f\u304a\u4ed8\u304d\u5408\u3044\u304f\u3060\u3055\u3044\u3002\u3067\u3082\u3001\u4ed6\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u306e\u65e5\u6642\u306e\u6271\u3044\u3067\u3082\u4f3c\u305f\u8003\u3048\u65b9\u3092\u3059\u308b\u306e\u3067\u3001\u6c7a\u3057\u3066\u7121\u99c4\u306b\u306f\u306a\u308a\u307e\u305b\u3093\u3088<span>!!<\/span><\/p>\n<h3><span id=\"-Date\">\uff11-\uff11\uff0eDate\u306f\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3092\u8868\u3059\u3082\u306e<\/span><\/h3>\n<p>Date\u306f\u3001<strong>\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3092\u8868\u3059\u30af\u30e9\u30b9<\/strong>\u3067\u3059\u3002\u3053\u306e\u6587\u7ae0\u3092\u66f8\u3044\u3066\u3044\u308b\u306e\u306f\u3001\u897f\u66a6<span>2019<\/span>\u5e74<span>6<\/span>\u6708<span>6<\/span>\u65e5<span>23<\/span>\u6642<span>40<\/span>\u5206<span>28<\/span>\u79d2\u304f\u3089\u3044<span>(<\/span>\u30df\u30ea\u79d2\u306e\u5358\u4f4d\u306f\u5206\u304b\u308a\u307e\u305b\u3093<span>\u2026)<\/span>\u3067\u3001\u3053\u306e\u300c\u77ac\u9593\u300d\u306e\u65e5\u6642\u3092\u30df\u30ea\u79d2\u307e\u3067\u3067\u8868\u73fe\u3059\u308b\u306e\u304c<span>Date<\/span>\u3067\u3059\u3002<\/p>\n<p>\u305d\u3057\u3066\u3001<span>Date<\/span>\u306f\u30df\u30ea\u79d2\u307e\u3067\u306e\u5177\u4f53\u7684\u306a\u65e5\u6642\u3092\u5fc5\u305a\u6301\u3063\u3066\u3044\u308b\u30e2\u30ce\u3067\u3059\u3002\u4eba\u9593\u306e\u611f\u899a\u3067\u306e<span>2019<\/span>\u5e74<span>6<\/span>\u6708<span>6<\/span>\u65e5<span>23<\/span>\u6642<span>40<\/span>\u5206<span>28<\/span>\u79d2\u300c\u304f\u3089\u3044\u300d\u3067\u306f\u306a\u304f\u3001<span>2019<\/span>\u5e74<span>6<\/span>\u6708<span>6<\/span>\u65e5<span>23<\/span>\u6642<span>40<\/span>\u5206<span>28<\/span>\u79d2<span>123<\/span>\u30df\u30ea\u79d2\u3068\u3044\u3046\u3088\u3046\u306b\u3001\u30df\u30ea\u79d2\u307e\u3067\u306f\u3063\u304d\u308a\u3068\u3001\u3067\u3059\u3002<\/p>\n<h3><span id=\"-Date19700101_000000GMT\">\uff11-\uff12\uff0e\u3010\u91cd\u8981\u3011<span>Date<\/span>\u304c\u6301\u3064\u306e\u306f<span>1970\/01\/01 00:00:00(GMT)<\/span>\u304b\u3089\u306e\u7d4c\u904e\u30df\u30ea\u79d2<\/span><\/h3>\n<p>\u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u3067\u65e5\u6642\u3092\u8868\u73fe\u3059\u308b\u65b9\u6cd5\u306b\u306f\u3001\u5927\u304d\u304f\u5206\u3051\u308b\u3068\u4ee5\u4e0b\u306e\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\u3002<span>Date<\/span>\u306f\u524d\u8005\u3067\u65e5\u6642\u3092\u8868\u73fe\u3059\u308b\u3082\u306e\u3067\u3059\u3002<\/p>\n<ol>\n<li>\u7279\u5b9a\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593<span>(<\/span>\u5dee\u5206<span>)<\/span>\u306e\u6574\u6570\u3067\u8868\u3059<\/li>\n<li>\u5e74\u6708\u65e5\u6642\u5206\u79d2\u306a\u3069\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3054\u3068\u306e\u6570\u5024\u3092\u6301\u3064\u4e00\u3064\u306e\u30c7\u30fc\u30bf\u69cb\u9020\u3067\u8868\u3059<\/li>\n<li>\u6c7a\u307e\u3063\u305f\u5f62\u5f0f\u306e\u6587\u5b57\u5217\u3084\u6570\u5b57\u3067\u6301\u3063\u3066\u304a\u3044\u3066\u3001\u5fc5\u8981\u306a\u6642\u306b\u89e3\u6790\u3057\u3066\u4f7f\u3046<\/li>\n<\/ol>\n<p>Date\u3067\u306f\u3001\u7d4c\u904e\u6642\u9593\u306e\u5358\u4f4d\u306f\u30df\u30ea\u79d2<span>(<\/span>\u4ee5\u4e0b\u3001<span>ms)<\/span>\u3067\u3059\u3002\u7d4c\u904e\u6642\u9593\u306e\u57fa\u6e96\u65e5\u6642\u306f\u3001\u897f\u66a6<span>1970<\/span>\u5e74<span>1<\/span>\u6708<span>1<\/span>\u65e5<span>0<\/span>\u6642<span>0<\/span>\u5206<span>0<\/span>\u79d2<span>(GMT)<\/span>\u3067\u3059\u3002\u3053\u306e\u7d4c\u904e\u30df\u30ea\u79d2\u3092\u30a8\u30dd\u30c3\u30af<span>(epoch)<\/span>\u30df\u30ea\u79d2\u3068\u547c\u3076\u3053\u3068\u304c\u3042\u308a\u3001\u79d2\u306e\u5834\u5408\u306f<span>UNIX<\/span>\u6642\u9593\u3068\u3082\u547c\u3070\u308c\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3068\u3057\u3066\u3001<span>1,000<\/span>\u306f<span>1970<\/span>\u5e74<span>1<\/span>\u6708<span>1<\/span>\u65e5<span>0<\/span>\u6642<span>0<\/span>\u5206<span>1<\/span>\u79d2<span>0<\/span>\u3001<span>1,559,832,028,123<\/span>\u306f<span>2019<\/span>\u5e74<span>6<\/span>\u6708<span>6<\/span>\u65e5<span>23<\/span>\u6642<span>40<\/span>\u5206<span>28<\/span>\u79d2<span>123<\/span>\u3067\u3059\u3002\u3061\u306a\u307f\u306b\u3001<span>1<\/span>\u5206\u306f<span>60,000ms<\/span>\u3001<span>1<\/span>\u6642\u9593\u306f<span>3,600,000ms<\/span>\u3001<span>1<\/span>\u65e5\u306f<span>86,400,000ms<\/span>\u3001<span>365<\/span>\u65e5\u306f<span>31,536,000,000ms<\/span>\u3067\u3059\u3002<\/p>\n<p>Date\u3067\u306e\u7d4c\u904e\u6642\u9593\u306f<span>long<\/span>\u3067\u8868\u3057\u307e\u3059\u3002\u4f8b\u306e\u3088\u3046\u306b\u3001\u5927\u304d\u306a\u6841\u306e\u6574\u6570\u306b\u306a\u308b\u304b\u3089\u3067\u3059\u3002<span>int<\/span>\u3067\u306f<span>\u00b121<\/span>\u5104\u7a0b\u5ea6\u306e\u6570\u5b57\u3092\u8868\u73fe\u3067\u304d\u307e\u3059\u304c\u3001\u305d\u308c\u3067\u3082\u6841\u304c\u3042\u307e\u308a\u306b\u5c0f\u3055\u3059\u304e\u3001<span>1970<\/span>\u5e74<span>1<\/span>\u6708<span>26<\/span>\u65e5<span>5<\/span>\u6642<span>31<\/span>\u5206<span>23<\/span>\u79d2<span>647<\/span>\u307e\u3067\u3057\u304b\u8868\u305b\u307e\u305b\u3093\u3002<\/p>\n<h4>\uff11-\uff12-\uff11\uff0e\u306a\u305c\u7d4c\u904e\u6642\u9593\u3067\u8868\u73fe\u3059\u308b\u306e\u304b<span>?<\/span><\/h4>\n<p>\u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u3067\u306f\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u3067\u65e5\u6642\u3092\u8868\u73fe\u3059\u308b\u65b9\u6cd5\u304c\u3088\u304f\u898b\u3089\u308c\u307e\u3059\u3002\u3064\u307e\u308a\u3001<span>1000<\/span>\u306a\u3069\u306e\u5177\u4f53\u7684\u306a\u6574\u6570\u3092\u3001\u65e5\u6642\u3068\u3057\u3066\u5185\u90e8\u3067\u4f7f\u3046\u306e\u3067\u3059\u3002\u3053\u308c\u306f\u3001\u6574\u6570\u3067\u8868\u73fe\u3055\u308c\u3066\u3044\u308b\u65b9\u304c\u3001\u51e6\u7406\u3092\u9ad8\u901f\u5316\u3067\u304d\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u7d4c\u904e\u6642\u9593\u306e\u6574\u6570\u306b\u3059\u308c\u3070\u3001\u65e5\u6642\u306b\u95a2\u3059\u308b\u8a08\u7b97\u306f\u3059\u3079\u3066\u6574\u6570\u306e\u8db3\u3057\u7b97\u3084\u5f15\u304d\u7b97\u306b\u306a\u308b\u306e\u3067\u3001\u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u304c\u3068\u3066\u3082\u9ad8\u901f\u306b\u51e6\u7406\u3067\u304d\u307e\u3059\u3002\u305d\u306e\u4ee3\u308f\u308a\u3001\u4eba\u9593\u8996\u70b9\u3067\u306f\u76f4\u611f\u7684\u306b\u306f\u5206\u304b\u308a\u3065\u3089\u3044\u3082\u306e\u306b\u306a\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u3051\u308c\u3069\u3082\u3002<\/p>\n<p>\u306a\u304a\u3001<span>UNIX<\/span>\u306e\u3044\u308f\u3086\u308b<span>2038<\/span>\u5e74\u554f\u984c\u3082\u3001\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u79d2\u306e\u5dee\u5206\u3067\u65e5\u6642\u3092\u8868\u73fe\u3057\u3066\u3044\u308b\u304b\u3089\u8d77\u304d\u308b\u3082\u306e\u3067\u3059\u3002<span>UNIX<\/span>\u6642\u9593\u306f\u79d2\u5358\u4f4d\u3067\u3059\u304c\u3001\u305d\u308c\u3067\u3082\u3044\u3064\u304b\u306f\u7d4c\u904e\u6642\u9593\u306e\u6570\u5024\u578b\u3067\u306e\u6700\u5927\u5024\u307e\u3067\u5230\u9054\u3059\u308b\u3053\u3068\u304c\u3042\u308b\u306e\u3067\u3059\u3002<\/p>\n<p>\u3067\u3082\u3001\u5148\u307b\u3069\u304a\u4f1d\u3048\u3057\u305f\u3068\u304a\u308a\u3001<span>Java<\/span>\u306e<span>Date<\/span>\u306f<span>64bit<\/span>\u306e<span>long<\/span>\u3067\u5dee\u5206\u3092\u8868\u73fe\u3057\u3066\u3044\u307e\u3059\u3002<span>long<\/span>\u306e\u6700\u5927\u5024\u3067\u306f\u3001<span>292,278,994<\/span>\u5e74\u304f\u3089\u3044\u307e\u3067\u8868\u73fe\u3067\u304d\u307e\u3059\u306e\u3067\u3001\u307e\u3042\u3001\u4eba\u985e\u304c\u751f\u304d\u6b8b\u3063\u3066\u3044\u305d\u3046\u306a\u9593\u306f\u5b89\u5fc3\u3057\u3066\u4f7f\u3048\u305d\u3046\u3067\u3059\u306d<span>!!<\/span><\/p>\n<h3><span id=\"i\">\uff11-\uff13\uff0e\u57fa\u6e96\u65e5\u6642\u3088\u308a\u4ee5\u524d\u306f\u30de\u30a4\u30ca\u30b9\u306e\u7d4c\u904e\u30df\u30ea\u79d2\u3067\u8868\u73fe\u3059\u308b<\/span><\/h3>\n<p>\u5148\u307b\u3069\u306e\u4f8b\u3067\u306f\u3001\u57fa\u6e96\u65e5\u6642\u3088\u308a\u672a\u6765\u306e\u65e5\u6642\u3068\u3057\u307e\u3057\u305f\u304c\u3001\u3082\u3061\u308d\u3093\u57fa\u6e96\u65e5\u6642\u3088\u308a\u524d\u306e\u65e5\u6642\u3082\u8868\u305b\u307e\u3059\u3002\u57fa\u6e96\u65e5\u6642\u4ee5\u524d\u306f\u3001\u30de\u30a4\u30ca\u30b9\u306e\u7d4c\u904e\u6642\u9593\u3067\u8868\u73fe\u3057\u307e\u3059\u3002\u3064\u307e\u308a\u3001<span>-86,400,000<\/span>\u306f<span>1969<\/span>\u5e74<span>12<\/span>\u6708<span>31<\/span>\u65e5<span>0<\/span>\u6642<span>0<\/span>\u5206<span>0<\/span>\u79d2<span>0<\/span>\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<h3><span id=\"-Date-2\">\uff11-\uff14\uff0eDate\u305d\u306e\u3082\u306e\u306b\u306f\u5e74\u6708\u65e5\u3084\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306e\u6982\u5ff5\u306f\u306a\u3044<\/span><\/h3>\n<p>\u3053\u3053\u307e\u3067\u8aac\u660e\u3057\u3066\u304d\u305f\u3053\u3068\u304b\u3089\u304a\u5206\u304b\u308a\u3044\u305f\u3060\u3051\u305f\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u304c\u3001<span>Date<\/span>\u305d\u306e\u3082\u306e\u306b\u306f\u5e74\u6708\u65e5\u3084\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306e\u8003\u3048\u65b9\u306f\u3042\u308a\u307e\u305b\u3093\u3002<span>Date<\/span>\u304c\u6301\u3063\u3066\u3044\u308b\u306e\u306f\u3001\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u30df\u30ea\u79d2\u6570\u3060\u3051\u3067\u3059\u3002<\/p>\n<p>\u3067\u3059\u306e\u3067\u3001<span>Date<\/span>\u3060\u3051\u3067\u306f\u3001<span>Date<\/span>\u304c\u8868\u73fe\u3059\u308b\u65e5\u6642\u304c\u4f55\u5e74\u4f55\u6708\u4f55\u65e5\u306a\u306e\u304b\u3001\u4f55\u66dc\u65e5\u306a\u306e\u304b\u3001\u3042\u308b\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3067\u306f\u4f55\u6642\u306b\u306a\u308b\u304b\u3001\u306a\u3069\u306e\u51e6\u7406\u306f\u884c\u3048\u307e\u305b\u3093\u3002\u7d4c\u904e\u30df\u30ea\u79d2\u304b\u3089\u306e\u8a08\u7b97\u306f\u4e00\u5fdc\u3067\u304d\u307e\u3059\u304c\u3001\u305d\u306e\u8a08\u7b97\u306f\u304b\u306a\u308a\u9762\u5012\u3067\u3059\u3002<\/p>\n<p>\u305d\u3093\u306a\u65e5\u6642\u95a2\u9023\u306e\u51e6\u7406\u306f\u3001<span>Date<\/span>\u3068\u306f\u5225\u306e\u30af\u30e9\u30b9\u304c\u62c5\u5f53\u3057\u307e\u3059\u3002\u4f8b\u3048\u3070\u3001<span>java.util.Calendar<\/span>\u3084\u3001<span>java.text.SimpleDateFormat<\/span>\u306a\u3069\u3067\u3059\u3002\u3067\u3059\u304b\u3089\u3001<span>Java<\/span>\u3067\u306e\u65e5\u6642\u51e6\u7406\u306f\u3001\u3044\u304f\u3064\u304b\u306e\u30af\u30e9\u30b9\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u884c\u3046\u3082\u306e\u306a\u306e\u3067\u3059\u3002<\/p>\n<h3><span id=\"-Date-3\">\uff11-\uff15\uff0eDate\u304c\u6301\u3064\u7d4c\u904e\u30df\u30ea\u79d2\u306f\u5909\u66f4\u3067\u304d\u306a\u3044<\/span><\/h3>\n<p>Date\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u6301\u3064\u7d4c\u904e\u30df\u30ea\u79d2\u306f\u3001\u5f8c\u304b\u3089\u5909\u66f4\u304c\u3067\u304d\u307e\u305b\u3093\u3002\u3064\u307e\u308a\u3001\u4e00\u56de\u4f5c\u3063\u305f<span>Date<\/span>\u306e\u65e5\u6642\u306f\u56fa\u5b9a\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u3092<span>Date<\/span>\u306f\u30a4\u30df\u30e5\u30fc\u30bf\u30d6\u30eb<span>(Immutable<\/span>\u3001\u5909\u66f4\u3067\u304d\u306a\u3044<span>)<\/span>\u3067\u3042\u308b\u3001\u3068\u3082\u8a00\u3046\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\u3067\u3059\u306e\u3067\u3001\u7279\u5b9a\u306e\u65e5\u6642\u3092\u8868\u3059<span>Date<\/span>\u306b\u5bfe\u3057\u3066\u3001\u4f8b\u3048\u3070\u305d\u306e<span>1<\/span>\u65e5\u5f8c\u3092\u8868\u3059<span>Date<\/span>\u304c\u5fc5\u8981\u306b\u306a\u3063\u305f\u3068\u3059\u308c\u3070\u3001\u65b0\u3057\u3044<span>Date<\/span>\u3092\u305d\u306e\u90fd\u5ea6\u4f5c\u308a\u76f4\u3059\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u3053\u308c\u3082\u3001<span>Date<\/span>\u304c\u6301\u3064\u7d4c\u904e\u30df\u30ea\u79d2\u3078\u8db3\u3057\u7b97\u5f15\u304d\u7b97\u3092\u3059\u308c\u3070\u8a08\u7b97\u306f\u3067\u304d\u307e\u3059\u304c\u3001\u5c11\u3005\u5206\u304b\u308a\u3065\u3089\u3044\u3067\u3059\u3088\u306d\u3002\u5148\u307b\u3069\u5c11\u3057\u540d\u524d\u306e\u51fa\u305f\u30af\u30e9\u30b9<span>Calendar<\/span>\u306f\u3001\u305d\u3093\u306a\u3088\u304f\u3042\u308b\u65e5\u6642\u306e\u8a08\u7b97\u306b\u4f7f\u3046\u30e1\u30bd\u30c3\u30c9\u3092\u6301\u3063\u3066\u3044\u305f\u308a\u3082\u3057\u307e\u3059\u3002<\/p>\n<h2><span id=\"JavaDate-2\">\uff12\uff0e\u3010Java\u3011Date\u306e\u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9<\/span><\/h2>\n<p>\u3053\u3053\u307e\u3067\u3001<span>Date<\/span>\u306e\u524d\u63d0\u77e5\u8b58\u306e\u3054\u8aac\u660e\u306b\u304a\u4ed8\u304d\u5408\u3044\u3044\u305f\u3060\u304d\u3001\u3042\u308a\u304c\u3068\u3046\u3054\u3056\u3044\u307e\u3057\u305f\u3002\u3053\u3053\u304b\u3089\u306f\u3001\u3055\u3063\u305d\u304f<span>Date<\/span>\u306e\u4f7f\u3044\u65b9\u3092\u7d39\u4ecb\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<h3><span id=\"-Date-4\">\uff12-\uff11\uff0eDate\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u4f5c\u308a\u65b9<\/span><\/h3>\n<p>Date\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u4f5c\u308a\u65b9\u306b\u306f\u3044\u304f\u3064\u304b\u306e\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u306f\u3001\u305d\u308c\u305e\u308c\u3092\u8aac\u660e\u3057\u3066\u3044\u304d\u307e\u3059\u3002<\/p>\n<h4>\uff12-\uff11-\uff11\uff0eDate\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u73fe\u5728\u65e5\u6642\u306e<span>Date<\/span>\u3092\u4f5c\u308b<\/h4>\n<p>Date\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u4f7f\u3063\u3066\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308b\u3068\u3001\u73fe\u5728\u65e5\u6642\u3092\u6301\u3063\u305f<span>Date<\/span>\u304c\u5f97\u3089\u308c\u307e\u3059\u3002\u3053\u306e\u73fe\u5728\u65e5\u6642\u306f\u3001<span>Java<\/span>\u3092\u52d5\u304b\u3057\u305f\u30d1\u30bd\u30b3\u30f3\u3084\u30b5\u30fc\u30d0\u306b\u8a2d\u5b9a\u3055\u308c\u3066\u3044\u308b\u73fe\u5728\u65e5\u6642\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date();\r\nSystem.out.println(d); \/\/ \u2192 Fri Jun 07 01:28:25 GMT+09:00 2019<\/pre>\n<h4>\uff12-\uff11-\uff12\uff0eDate\u306e\u5f15\u6570\u3042\u308a\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067\u6307\u5b9a\u3057\u305f\u65e5\u6642\u306e<span>Date<\/span>\u3092\u4f5c\u308b<\/h4>\n<p>Date\u306e<span>long<\/span>\u3092\u5f15\u6570\u306b\u53d6\u308b\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u4f7f\u3063\u3066\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308b\u3068\u3001<span>1970\/1\/1 00:00:00<\/span>\u304b\u3089\u6307\u5b9a\u3057\u305f\u3060\u3051\u306e\u7d4c\u904e\u6642\u9593\u3092\u6301\u3064<span>Date<\/span>\u3092\u4f5c\u308c\u307e\u3059\u3002\u3053\u306e<span>long<\/span>\u306f\u3001\u305a\u3063\u3068\u304a\u8a71\u3057\u3066\u304d\u305f\u901a\u308a\u3001\u7d4c\u904e\u6642\u9593\u306e\u30df\u30ea\u79d2\u8868\u73fe\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date(1000 * 60 * 60 * 24); \/\/ 1\u65e5\u5206\u306e\u7d4c\u904e\u30df\u30ea\u79d2(86400000ms)\u3092\u6307\u5b9a\u3057\u3066Date\u3092\u4f5c\u308b\u3068\u2026\r\nSystem.out.println(d); \/\/ \u2192 Fri Jan 02 09:00:00 GMT+09:00 1970\u30011\u65e5\u5f8c\u306b\u306a\u3063\u305f<\/pre>\n<h4>\uff12-\uff11-\uff13\uff0eDateFormat.parse\u3067\u3001\u65e5\u6642\u3092\u8868\u3059\u6587\u5b57\u5217\u304b\u3089Date\u3092\u4f5c\u308b<\/h4>\n<p>Date\u306f\u6587\u5b57\u5217\u304b\u3089\u3082\u4f5c\u308c\u307e\u3059\u3002\u305d\u306e\u969b\u306b\u306f\u3001<span>java.text.DateFormat<\/span>\u306e\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u3042\u308b\u3001<span>java.text.SimpleDateFormat<\/span>\u306e\u30e1\u30bd\u30c3\u30c9<span>parse<\/span>\u3092\u4f7f\u3046\u306e\u304c\u666e\u901a\u3067\u3059\u3002<span>parse<\/span>\u306f\u3001\u89e3\u6790\u3059\u308b\u3068\u3044\u3063\u305f\u610f\u5473\u306e\u8a00\u8449\u3067\u3059\u3002<\/p>\n<blockquote>\n<p>DateFormat (Java SE 12 &amp; JDK 12)<\/p>\n<p><a href=\"https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/text\/DateFormat.html\">https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/text\/DateFormat.html<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>SimpleDateFormat (Java SE 12 &amp; JDK 12)<\/p>\n<p><a href=\"https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/text\/SimpleDateFormat.html\">https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/text\/SimpleDateFormat.html<\/a><\/p>\n<\/blockquote>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSSXXX\");\r\nDate d = df.parse(\"2019\/06\/06 23:40:28.123+00:00\");\r\nSystem.out.println(d); \/\/ \u2192 Fri Jun 07 08:40:28 GMT+09:00 2019<\/pre>\n<p>\u65e5\u6642\u306e\u6587\u5b57\u5217\u306e\u66f8\u5f0f\u306f\u3001<span>SimpleDateFormat<\/span>\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306e\u5f15\u6570\u3067\u6307\u5b9a\u3057\u307e\u3059\u3002\u65e5\u672c\u3067\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u4f5c\u308b\u306a\u3089\u3001\u4ee5\u4e0b\u306e\u3069\u308c\u304b\u304b\u3001\u7d44\u307f\u5408\u308f\u305b\u308c\u3070<span>OK<\/span>\u3067\u3057\u3087\u3046\u3002\u6642\u5206\u79d2\u3084\u30df\u30ea\u79d2\u304c\u4e0d\u8981\u306a\u3089\u3001\u305d\u306e\u90e8\u5206\u3092\u524a\u9664\u3057\u307e\u3059\u3002<\/p>\n<table border=\"1\" style=\"border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr style=\"height: 24px;\">\n<td style=\"width: 38.8416%; height: 24px;\">\u66f8\u5f0f\u6587\u5b57\u5217<\/td>\n<td style=\"width: 61.1584%; height: 24px;\">\u89e3\u91c8\u3067\u304d\u308b\u65e5\u6642\u306e\u4f8b<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 38.8416%; height: 24px;\">yyyyMMddHHmmssSSS<\/td>\n<td style=\"width: 61.1584%; height: 24px;\">20190102123456123<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 38.8416%; height: 24px;\">yyyy\/MM\/dd HH:mm:ss.SSS<\/td>\n<td style=\"width: 61.1584%; height: 24px;\">2019\/01\/02 12:34:56.123<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 38.8416%; height: 24px;\">yyyy-MM-dd HH:mm:ss.SSS<\/td>\n<td style=\"width: 61.1584%; height: 24px;\">2019-01-02 12:34:56.123<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 38.8416%; height: 24px;\">yyyy\/MM\/dd HH:mm:ssXXX<\/td>\n<td style=\"width: 61.1584%; height: 24px;\">2019\/01\/02 12:34:56+09:00<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 38.8416%; height: 24px;\">yyyy-MM-dd&#8217;T&#8217;HH:mm:ssXXX<\/td>\n<td style=\"width: 61.1584%; height: 24px;\">2019-01-02T12:34:56+09:00<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u306a\u304a\u3001\u6642\u5206\u79d2\u3084\u30df\u30ea\u79d2\u306e\u5024\u304c\u672a\u6307\u5b9a\u306a\u3089\u3001\u305d\u306e\u90e8\u5206\u306e\u5024\u306f<span>0<\/span>\u306b\u306a\u308a\u307e\u3059\u3002\u3064\u307e\u308a\u3001\u5024<span>&#8220;2019\/01\/01&#8221;<\/span>\u3092\u3001\u66f8\u5f0f<span>&#8220;yyyy\/MM\/dd&#8221;<\/span>\u3067<span>parse<\/span>\u3057\u3066\u4f5c\u3063\u305f<span>Date<\/span>\u306f\u3001<span>2019\/01\/01 00:00:00.000<\/span>\u3092\u6301\u3064<span>Date<\/span>\u306b\u306a\u308b\u3001\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>SimpleDateFormat\u3067\u6307\u5b9a\u3067\u304d\u308b\u66f8\u5f0f\u306e\u8a73\u7d30\u306f\u3001\u5f8c\u306e\u7ae0\u3067\u3082\u3046\u5c11\u3057\u3060\u3051\u7d30\u304b\u304f\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002\u5b8c\u5168\u306a\u66f8\u5f0f\u306e\u4ed5\u69d8\u306b\u3064\u3044\u3066\u306f\u3001<span>SimpleDateFormat<\/span>\u306e<span>Javadoc<\/span>\u3092\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u306a\u304a\u3001<span>SimpleDateFormat<\/span>\u304c\u65e5\u6642\u3092\u89e3\u6790\u3059\u308b\u969b\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u610f\u8b58\u3059\u3079\u304d\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u308c\u306b\u3064\u3044\u3066\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u304c\u3001\u89e3\u6790\u7d50\u679c\u304c\u4e88\u671f\u305b\u306c\u65e5\u6642\u306b\u306a\u308b\u6642\u306f\u3001\u66f8\u5f0f\u306e\u9593\u9055\u3044\u304b\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u7591\u3044\u307e\u3057\u3087\u3046\u3002\u3002<\/p>\n<h4>\uff12-\uff11-\uff14\uff0eCalendar.getTime\u3067\u3001Calendar\u304c\u6301\u3064\u65e5\u6642\u304b\u3089Date\u3092\u4f5c\u308b<\/h4>\n<p>java.util.Calendar\u3082\u3001Java\u3067\u65e5\u6642\u3092\u6271\u3046\u305f\u3081\u306e\u30af\u30e9\u30b9\u306e\u4e00\u3064\u3067\u3059\u3002Calendar.getTime\u3067\u3001Calendar\u304c\u6301\u3064\u65e5\u6642\u3092Date\u3068\u3057\u3066\u53d6\u308a\u51fa\u305b\u307e\u3059\u3002<\/p>\n<blockquote>\n<p>Calendar (Java SE 12 &amp; JDK 12)<\/p>\n<p><a href=\"https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/util\/Calendar.html\">https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/util\/Calendar.html<\/a><\/p>\n<\/blockquote>\n<pre class=\"prettyprint lang:default decode:true\">Calendar c = Calendar.getInstance(); \/\/ \u73fe\u5728\u65e5\u6642\u3092\u6301\u3064Calendar\u3092\u751f\u6210\u3057\u3066\u3001\r\nDate d = c.getTime(); \/\/ Calendar\u304c\u6301\u3064\u65e5\u6642\u3092Date\u306b\u5909\u63db\u3059\u308b\u3068\u3001\r\nSystem.out.println(c); \/\/ \u2192 java.util.GregorianCalendar[time=1559839894431,\uff5e(\u4ee5\u4e0b\u3001\u9577\u3044\u306e\u3067\u5272\u611b)\r\nSystem.out.println(d); \/\/ \u2192 Fri Jun 07 01:51:34 GMT+09:00 2019<\/pre>\n<p>Calendar\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u65e5\u6642\u3092\u8a2d\u5b9a\u3057\u305f\u5f8c\u306b<span>getTime<\/span>\u3059\u308c\u3070\u3001\u5fc5\u8981\u306a\u65e5\u6642\u3092\u6301\u3063\u305f<span>Date<\/span>\u3092\u81ea\u7531\u306b\u4f5c\u308c\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Calendar c = Calendar.getInstance();\r\n\r\nc.set(Calendar.YEAR, 1970);\r\nc.set(Calendar.MONTH, 0); \/\/ \u6708\u306f0\u59cb\u307e\u308a\u30011\u6708\u306b\u3059\u308b\u306a\u30890\u304b\u3089\u3002\u3042\u308b\u3044\u306f\u2193\u306e\u3088\u3046\u306b\u3059\u308b\r\n\/\/ c.set(Calendar.MONTH, Calendar.JANUARY);\r\nc.set(Calendar.DAY_OF_MONTH, 1);\r\nc.set(Calendar.HOUR_OF_DAY, 0);\r\nc.set(Calendar.MINUTE, 0);\r\nc.set(Calendar.SECOND, 0);\r\nc.set(Calendar.MILLISECOND, 0);\r\n\r\nDate d = c.getTime(); \/\/\r\nSystem.out.println(d); \/\/ \u2192 Thu Jan 01 00:00:00 GMT+09:00 1970<\/pre>\n<p>\u305f\u3060\u3057\u3001\u5f8c\u8ff0\u3057\u307e\u3059\u304c\u3001<span>SimpleDateFormat<\/span>\u3068\u540c\u69d8\u306b\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306b\u3064\u3044\u3066\u306f\u8981\u6ce8\u610f\u3067\u3059\u3002\u3069\u3093\u306a\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u3067\u65e5\u6642\u3092\u6271\u3046\u6642\u3067\u3082\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3042\u308b\u3044\u306f\u6642\u5dee\u306e\u8003\u3048\u65b9\u306f\u3001\u5c11\u3005\u5206\u304b\u308a\u3065\u3089\u3044\u3082\u306e\u3067\u3059\u3002<\/p>\n<h4>\uff12-\uff11-\uff15\uff0eDate.from\u3067\u3001<span>Instant<\/span>\u304c\u6301\u3064\u65e5\u6642\u304b\u3089<span>Date<\/span>\u3092\u4f5c\u308b<\/h4>\n<p>Java 8\u4ee5\u964d\u3067\u4f7f\u3048\u308b\u65b0\u3057\u3044\u65e5\u6642\u306e\u6a19\u6e96<span>API<\/span>\u306b\u306f\u3001\u3042\u308b\u7279\u5b9a\u306e\u77ac\u9593\u3092\u8868\u3059<span>java.time.Instant<\/span>\u3068\u3044\u3046\u30af\u30e9\u30b9\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u306e<span>Instant<\/span>\u304b\u3089\u3082\u3001<span>Date.from<\/span>\u3092\u4f7f\u3063\u3066<span>Date<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u308c\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Instant i = Instant.now(); \/\/ \u73fe\u5728\u306e\u65e5\u6642\u306eInstant\u3092\u4f5c\u3063\u3066\u3001\r\nDate d = Date.from(i); \/\/ \u305d\u306eInstant\u304b\u3089Date\u3092\u4f5c\u308b\r\nSystem.out.println(i); \/\/ \u2192 2019-06-06T16:58:32.055471300Z\r\nSystem.out.println(d); \/\/ \u2192 Fri Jun 07 01:58:32 GMT+09:00 2019<\/pre>\n<p>\u3042\u308b\u3044\u306f\u3001<span>Instant.toEpochMilli<\/span>\u3092\u4f7f\u3063\u3066\u7d4c\u904e\u30df\u30ea\u79d2\u306e<span>long<\/span>\u306b\u5909\u63db\u3057\u3001\u305d\u306e<span>long<\/span>\u3067<span>Date<\/span>\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3092\u547c\u3073\u51fa\u3057\u3066\u3082<span>OK<\/span>\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Instant i = Instant.now();\r\nDate d = new Date(i.toEpochMilli());\r\nSystem.out.println(i); \/\/ \u2192 2019-06-06T16:59:38.521718400Z\r\nSystem.out.println(d); \/\/ \u2192 Fri Jun 07 01:59:38 GMT+09:00 2019<\/pre>\n<h4>\uff12-\uff11-\uff16\uff0eDate\u306e<span>deprecated<\/span>\u306a\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306f\u4f7f\u308f\u306a\u3044<\/h4>\n<p>Date\u306e<span>Javadoc<\/span>\u306b\u306f\u3001\u3053\u3053\u3067\u7d39\u4ecb\u3057\u305f\u30c7\u30d5\u30a9\u30eb\u30c8\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3001<span>long<\/span>\u3092\u5f15\u6570\u306b\u53d6\u308b\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306e\u4ed6\u306b\u3082\u3001\u5e74\u6708\u65e5\u3001\u6642\u5206\u79d2\u306a\u3069\u3092\u6307\u5b9a\u3067\u304d\u308b\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u304c\u3044\u304f\u3064\u304b\u30aa\u30fc\u30d0\u30fc\u30ed\u30fc\u30c9\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date(2019, 1, 2, 12, 34, 56);\r\nSystem.out.println(d); \/\/ \u2192 Sun Feb 02 12:34:56 GMT+09:00 3919<\/pre>\n<p>\u3053\u308c\u3089\u306e\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u306f\u3001\u4f7f\u3046\u3053\u3068\u304c\u63a8\u5968\u3055\u308c\u3066\u3044\u307e\u305b\u3093\u306e\u3067<span>(deprecated)<\/span>\u3001\u4f7f\u308f\u306a\u3044\u3053\u3068\u3092\u304a\u52e7\u3081\u3057\u307e\u3059\u3002\u904e\u53bb\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u3068\u306e\u4e92\u63db\u6027\u306e\u305f\u3081\u306b\u307e\u3060\u6b8b\u3055\u308c\u3066\u306f\u3044\u307e\u3059\u304c\u3001\u3044\u3064\u524a\u9664\u3055\u308c\u3066\u3082\u304a\u304b\u3057\u304f\u306f\u306a\u3044\u3082\u306e\u3067\u3059\u3002<\/p>\n<p>Date\u306f\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u3092\u6301\u3064\u3060\u3051\u306e\u3082\u306e\u306a\u306e\u3067\u3001\u5e74\u6708\u65e5\u6642\u5206\u79d2\u306a\u3069\u306e\u8996\u70b9\u3067\u306e\u751f\u6210\u30fb\u64cd\u4f5c\u304c\u5fc5\u8981\u306a\u5834\u5408\u306f\u3001<span>Java<\/span>\u3067\u306f<span>Calendar<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<p>\u306a\u304a\u3001<span>Java<\/span>\u306f\u3001<span>deprecated<\/span>\u306a\u3082\u306e<span>(<\/span>\u30af\u30e9\u30b9\u3001\u30e1\u30bd\u30c3\u30c9\u306a\u3069<span>)<\/span>\u3092\u3001\u904e\u53bb\u304b\u3089\u306e\u4e92\u63db\u6027\u3092\u7dad\u6301\u3059\u308b\u305f\u3081\u306b\u6b8b\u3059\u65b9\u91dd\u3092\u7d9a\u3051\u3066\u304d\u307e\u3057\u305f\u3002\u3067\u3082\u3001\u6700\u8fd1\u3067\u306f\u305d\u3046\u3044\u3046\u30ec\u30ac\u30b7\u30fc\u306a\u3082\u306e\u304c\u524a\u9664\u3055\u308c\u308b\u4f8b\u304c\u51fa\u3066\u304d\u3066\u3044\u307e\u3059\u3002\u6c17\u3092\u4ed8\u3051\u307e\u3057\u3087\u3046\u3002<\/p>\n<h3><span id=\"i-2\">\uff12-\uff12\uff0e\u7d4c\u904e\u30df\u30ea\u79d2\u306e\u53d6\u5f97<\/span><\/h3>\n<p>Date\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304b\u3089\u7d4c\u904e\u6642\u9593\u306e\u30df\u30ea\u79d2\u3092\u53d6\u5f97\u3059\u308b\u306b\u306f\u3001<span>Date.getTime<\/span>\u3092\u547c\u3073\u51fa\u3057\u307e\u3059\u3002\u3059\u308b\u3068\u3001\u305d\u306e\u6642\u9593\u3092\u6301\u3063\u305f<span>long<\/span>\u304c\u623b\u3063\u3066\u304d\u307e\u3059\u3002\u57fa\u6e96\u65e5\u6642\u3088\u308a\u904e\u53bb\u306e\u65e5\u6642\u3092\u8868\u3059<span>Date<\/span>\u306a\u3089\u3001\u30de\u30a4\u30ca\u30b9\u306e<span>long<\/span>\u304c\u623b\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date();\r\nlong time = d.getTime();\r\nSystem.out.println(time); \/\/ \u2192 1559864448025<\/pre>\n<p>\u7d4c\u904e\u6642\u9593\u306e\u30df\u30ea\u79d2\u3092\u76f4\u63a5\u53d6\u308a\u51fa\u3057\u3066\u4f55\u304b\u610f\u5473\u304c\u3042\u308b\u306e\u304b<span>?<\/span>\u3068\u601d\u308f\u308c\u305f\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u304c\u3001\u65e5\u6642\u306e\u6570\u5024\u3092\u57fa\u306b\u3057\u3066\u8a08\u7b97\u3057\u305f\u3044\u6642\u306a\u3069\u306b\u3001\u7d50\u69cb\u4f7f\u3063\u305f\u308a\u3059\u308b\u3082\u306e\u3067\u3059\u3002<\/p>\n<h3><span id=\"-Date-5\">\uff12-\uff13\uff0eDate\u540c\u58eb\u306e\u6bd4\u8f03<\/span><\/h3>\n<p>Date\u540c\u58eb\u306e\u6bd4\u8f03\u306f\u3001\u65e5\u6642\u3092\u6271\u3046\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u306f\u983b\u7e41\u306b\u884c\u3044\u307e\u3059\u3002<span>Date<\/span>\u306f\u6bd4\u8f03\u306e\u305f\u3081\u306e\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30a4\u30b9<span>Comparable<\/span>\u3092\u5b9f\u88c5\u3057\u3066\u3044\u308b\u306e\u3067\u3001\u305d\u306e<span>compareTo<\/span>\u3092\u4f7f\u3063\u3066\u3082\u3044\u3044\u3067\u3059\u3057\u3001\u5c02\u7528\u306e\u6bd4\u8f03\u7528\u30e1\u30bd\u30c3\u30c9\u3082\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<h4>\uff12-\uff13-\uff11\uff0eDate\u306e\u5927\u5c0f\u95a2\u4fc2\u3068\u306f\u3069\u3046\u3044\u3046\u3082\u306e\u304b<\/h4>\n<p>\u65e5\u6642\u306e\u5927\u5c0f\u3068\u3001\u672a\u6765\u3068\u904e\u53bb\u3092\u7d10\u4ed8\u3051\u308b\u3068\u304d\u306f\u3001\u5c11\u3057\u6df7\u4e71\u3057\u304c\u3061\u3067\u3059\u3002<span>Date<\/span>\u3067\u306f\u3001\u4ee5\u4e0b\u306e\u30eb\u30fc\u30eb\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n<div class=\"attention a-2\">\n<ul>\n<li>Date1 &lt; Date2 \u2192 Date1\u306fDate2\u3088\u308a\u3082\u904e\u53bb\u3067\u3042\u308b<\/li>\n<li>Date1 == Date2 \u2192 Date1\u3068Date2\u306f\u540c\u3058\u65e5\u6642\u3067\u3042\u308b<\/li>\n<li>Date1 &gt; Date2 \u2192 Date1\u306fDate2\u3088\u308a\u3082\u672a\u6765\u3067\u3042\u308b<\/li>\n<\/ul>\n<\/div>\n<p>\u3064\u307e\u308a\u3001\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u304c\u5927\u304d\u3044\u65b9\u304c\u672a\u6765\u3001\u5c0f\u3055\u3044\u65b9\u304c\u904e\u53bb\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u308c\u306f<span>Date<\/span>\u304c\u5b9f\u969b\u306b\u6301\u3064\u5024\u304c\u3001\u7d4c\u904e\u6642\u9593\u306e<span>long<\/span>\u3067\u3042\u308b\u3068\u77e5\u3063\u3066\u3044\u308b\u3068\u3001\u7406\u89e3\u30fb\u7d0d\u5f97\u3057\u3084\u3059\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u8981\u6ce8\u610f\u306a\u306e\u306f\u3001<span>Date<\/span>\u304c\u6301\u3063\u3066\u3044\u308b\u30df\u30ea\u79d2\u5358\u4f4d\u306e\u65e5\u6642\u3067\u6bd4\u8f03\u3055\u308c\u308b\u3053\u3068\u3067\u3059\u3002\u6bd4\u8f03\u3059\u308b<span>Date<\/span>\u540c\u58eb\u3067<span>1<\/span>\u30df\u30ea\u79d2\u9055\u3063\u305f\u3060\u3051\u3067\u3082\u7d50\u679c\u306e\u5927\u5c0f\u306b\u53cd\u6620\u3055\u308c\u307e\u3059\u306e\u3067\u3001\u304a\u304b\u3057\u306a\u7d50\u679c\u306b\u306a\u308b\u3088\u3046\u306b\u898b\u3048\u308b\u306a\u3089\u7591\u3063\u3066\u3082\u3044\u3044\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002<\/p>\n<p>\u306a\u304a\u3001\u5b9f\u969b\u306e\u3068\u3053\u308d\u3001<span>Date<\/span>\u306e\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3067\u3082\u4ee5\u4e0b\u306e\u3088\u3046\u306b<span>long<\/span>\u540c\u58eb\u306e\u5358\u7d14\u306a\u5927\u5c0f\u6bd4\u8f03\u3092\u3057\u3066\u3044\u308b\u3060\u3051\u3060\u3063\u305f\u308a\u3057\u307e\u3059\u3002\u5b9f\u306b\u7c21\u5358\u306a\u30ed\u30b8\u30c3\u30af\u3067\u9ad8\u901f\u306b\u52d5\u304f\u3067\u3057\u3087\u3046\u304c\u3001\u524d\u8ff0\u3057\u305f\u6ce8\u610f\u3092\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u7406\u7531\u3067\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ Java 12\u306e\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3088\u308a\u629c\u7c8b\r\n    public int compareTo(Date anotherDate) {\r\n        long thisTime = getMillisOf(this);\r\n        long anotherTime = getMillisOf(anotherDate);\r\n        return (thisTime&lt;anotherTime ? -1 : (thisTime==anotherTime ? 0 : 1));\r\n    }<\/pre>\n<h4>\uff12-\uff13-\uff12\uff0eDate\u306e\u5927\u5c0f\u95a2\u4fc2\u3092<span>compareTo<\/span>\u3067\u78ba\u8a8d\u3059\u308b<\/h4>\n<p>\u3067\u306f\u3001<span>Date.compareTo<\/span>\u3092\u4f7f\u3063\u3066\u5927\u5c0f\u5224\u65ad\u3092\u3057\u3066\u307f\u307e\u3059\u3002<span>Comparable.compareTo<\/span>\u306e\u30eb\u30fc\u30eb\u306b\u5f93\u3063\u3066\u3001\u5c0f\u3055\u3044<span>(-1<\/span>\u4ee5\u4e0b<span>)<\/span>\u3001\u7b49\u3057\u3044<span>(0)<\/span>\u3001\u5927\u304d\u3044<span>(1<\/span>\u4ee5\u4e0a<span>)<\/span>\u306e<span>int<\/span>\u304c\u623b\u3063\u3066\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d1 = df.parse(\"2019\/06\/06 12:34:56.789\"); \/\/ \u30d9\u30fc\u30b9\u3068\u3059\u308b\u65e5\u6642\r\nDate d2 = df.parse(\"2019\/06\/06 12:35:56.789\"); \/\/ d1\u3088\u308a1\u5206\u672a\u6765\u306e\u65e5\u6642\r\nDate d3 = df.parse(\"2019\/06\/06 12:34:56.789\"); \/\/ d1\u3068\u540c\u3058\u65e5\u6642\r\n\r\nint d1_d2 = d1.compareTo(d2);\r\nint d2_d1 = d2.compareTo(d1);\r\nint d1_d3 = d1.compareTo(d3);\r\n\r\nSystem.out.println(d1_d2); \/\/ \u2192 -1\u3001d1 \u306f d2 \u3088\u308a\u904e\u53bb\u306e\u65e5\u6642\r\nSystem.out.println(d2_d1); \/\/ \u2192 1\u3001d2 \u306f d1 \u3088\u308a\u672a\u6765\u306e\u65e5\u6642\r\nSystem.out.println(d1_d3); \/\/ \u2192 0\u3001d1 \u3068 d3 \u306e\u65e5\u6642\u306f\u540c\u3058<\/pre>\n<p>\u3053\u3053\u3067\u3001<span>==<\/span>\u3084<span>&gt;<\/span>\u3001<span>&lt;<\/span>\u306a\u3069\u3067\u6bd4\u8f03\u3057\u3066\u306f\u3044\u3051\u307e\u305b\u3093\u3002<span>==<\/span>\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u540c\u3058\u304b\u78ba\u8a8d\u3059\u308b\u6f14\u7b97\u5b50\u306a\u306e\u3067\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304c\u6301\u3064\u65e5\u6642\u3067\u6bd4\u8f03\u3057\u307e\u305b\u3093\u3002\u305d\u3057\u3066\u3001<span>&gt;<\/span>\u3084<span>&lt;<\/span>\u306f\u6570\u5024\u7528\u306e\u6bd4\u8f03\u6f14\u7b97\u5b50\u306a\u306e\u3067\u3001<span>Date<\/span>\u3078\u306f\u4f7f\u3048\u307e\u305b\u3093\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d1 = df.parse(\"2019\/06\/06 12:34:56.789\");\r\nDate d2 = df.parse(\"2019\/06\/06 12:34:56.789\"); \/\/ d1\u3068\u540c\u3058\u65e5\u6642\u3060\u304c\u3001d1\u3068\u306f\u9055\u3046Date\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\r\n\r\nSystem.out.println(d1 == d2); \/\/ \u2192 false\u3001\u65e5\u6642\u306f\u540c\u3058\u3060\u3051\u308c\u3069\u3082\u3001\u9055\u3046\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u305f\u3081\r\nSystem.out.println(d1.compareTo(d2)); \/\/ \u2192 0\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f\u9055\u3046\u304c\u3001\u540c\u3058\u65e5\u6642\u306e\u305f\u3081<\/pre>\n<p>\u306a\u304a\u3001<span>Date<\/span>\u304c\u6301\u3064\u65e5\u6642\u3092\u3001\u5e74\u6708\u65e5\u3060\u3051\u306a\u3069\u3067\u5927\u5c0f\u6bd4\u8f03\u3057\u305f\u3044\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u5834\u5408\u306f<span>Date<\/span>\u3060\u3051\u3067\u306f\u7c21\u5358\u306b\u306f\u3067\u304d\u307e\u305b\u3093\u306e\u3067\u3001<span>Calendar<\/span>\u3084<span>SimpleDateFormat<\/span>\u3092\u7d44\u307f\u5408\u308f\u305b\u308b\u3068\u3044\u3044\u3067\u3057\u3087\u3046\u3002\u3084\u308a\u65b9\u306f\u5f8c\u8ff0\u3057\u307e\u3059\u3002<\/p>\n<h4>\uff12-\uff13-\uff13\uff0eDate\u306e\u5927\u5c0f\u95a2\u4fc2\u3092<span>Date.before\/after\/equals<\/span>\u3067\u78ba\u8a8d\u3059\u308b<\/h4>\n<p>compareTo\u306e\u7d50\u679c\u306f\u6570\u5024\u306a\u306e\u3067\u3001\u4eba\u9593\u5411\u3051\u306b\u306f\u3061\u3087\u3063\u3068\u4e0d\u89aa\u5207\u3067\u3059\u3002\u6570\u5b57\u306e\u8aad\u307f\u9055\u3044\u3067\u30d0\u30b0\u3092\u4f5c\u3063\u3066\u3057\u307e\u3046\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u3002\u904e\u53bb\u3001\u672a\u6765\u3001\u540c\u3058\u3068\u3044\u3046\u5224\u65ad\u3092\u30e1\u30bd\u30c3\u30c9\u3067\u8868\u73fe\u3067\u304d\u308c\u3070\u3001\u3082\u3046\u5c11\u3057\u8aad\u307f\u3084\u3059\u304f\u306a\u308a\u307e\u3059\u3088\u306d\u3002<\/p>\n<p>\u305d\u306e\u305f\u3081\u306e\u30e1\u30bd\u30c3\u30c9\u304c\u3001<span>Date.before\/after\/equals<\/span>\u3067\u3059\u3002\u7d50\u679c\u306f\u3059\u3079\u3066<span>boolean<\/span>\u3067\u623b\u308a\u307e\u3059\u3002\u3067\u3059\u306e\u3067\u3001\u4f8b\u3048\u3070<span>if<\/span>\u6587\u3067\u4f7f\u3048\u3070\u3001<span>compareTo<\/span>\u306e\u7d50\u679c\u3092\u6570\u5024\u3067\u5224\u65ad\u3059\u308b\u3088\u308a\u3082\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u76f4\u611f\u7684\u306b\u306a\u308b\u3067\u3057\u3087\u3046\u3002<\/p>\n<ul>\n<li>before \u2192 \u81ea\u8eab\u304c\u5f15\u6570\u306e<span>Date<\/span>\u3088\u308a\u3082\u904e\u53bb\u306a\u3089<span>true<\/span>\u3001\u305d\u3046\u3067\u306a\u3051\u308c\u3070<span>false<\/span><\/li>\n<li><span>equals \u2192 <\/span>\u81ea\u8eab\u304c\u5f15\u6570\u306e<span>Date<\/span>\u3068\u540c\u3058\u65e5\u6642\u306a\u3089<span>true<\/span>\u3001\u305d\u3046\u3067\u306a\u3051\u308c\u3070<span>false<\/span><\/li>\n<li><span>after \u2192 <\/span>\u81ea\u8eab\u304c\u5f15\u6570\u306e<span>Date<\/span>\u3088\u308a\u3082\u672a\u6765\u306a\u3089<span>true<\/span>\u3001\u305d\u3046\u3067\u306a\u3051\u308c\u3070<span>false<\/span><\/li>\n<\/ul>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d1 = df.parse(\"2019\/06\/06 12:34:56.789\");\r\nDate d2 = df.parse(\"2019\/06\/06 12:35:56.789\"); \/\/ d1\u306e1\u5206\u672a\u6765\u306e\u65e5\u6642\r\nDate d3 = df.parse(\"2019\/06\/06 12:34:56.789\"); \/\/ d1\u3068\u540c\u3058\u65e5\u6642\r\n\r\nboolean d1_before_d2 = d1.before(d2);\r\nboolean d2_before_d1 = d2.before(d1);\r\nboolean d1_after_d2 = d1.after(d2);\r\nboolean d2_after_d1 = d2.after(d1);\r\nboolean d1_equals_d3 = d1.equals(d3);\r\n\r\nSystem.out.println(d1_before_d2); \/\/ \u2192 true\u3001d1 \u306f d2 \u3088\u308a\u904e\u53bb\u306e\u65e5\u6642\u3067\u3042\u308b\r\nSystem.out.println(d2_before_d1); \/\/ \u2192 false\u3001d2 \u306f d1 \u3088\u308a\u904e\u53bb\u306e\u65e5\u6642\u3067\u306f\u306a\u3044\r\nSystem.out.println(d1_after_d2); \/\/ \u2192 false\u3001d1 \u306f d2 \u3088\u308a\u672a\u6765\u306e\u65e5\u6642\u3067\u306f\u306a\u3044\r\nSystem.out.println(d2_after_d1); \/\/ \u2192 true\u3001d2 \u306f d1 \u3088\u308a\u672a\u6765\u306e\u65e5\u6642\u3067\u3042\u308b\r\nSystem.out.println(d1_equals_d3); \/\/ \u2192 true\u3001d1 \u3068 d3 \u306e\u65e5\u6642\u306f\u540c\u3058\u3067\u3042\u308b<\/pre>\n<h4>\uff12-\uff13-\uff14\uff0eDate\u305d\u306e\u3082\u306e\u3092\u3001\u3042\u308b\u3044\u306f<span>Date<\/span>\u3092\u304b\u3089\u3081\u3066\u30bd\u30fc\u30c8\u3059\u308b<\/h4>\n<p>Date\u306fComparable\u3092\u5b9f\u88c5\u3057\u3066\u3044\u307e\u3059\u306e\u3067\u3001java.util.Collections.sort\u3084java.util.Arrays.sort\u306a\u3069\u3067\u3001\u305d\u306e\u307e\u307e\u30bd\u30fc\u30c8\u3067\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d1 = df.parse(\"2019\/06\/06 12:34:56.789\");\r\nDate d2 = df.parse(\"2019\/06\/06 12:35:56.789\"); \/\/ d1\u306e1\u5206\u672a\u6765\u306e\u65e5\u6642\r\nDate d3 = df.parse(\"2019\/06\/06 12:36:56.789\"); \/\/ d2\u306e1\u5206\u672a\u6765\u306e\u65e5\u6642\r\n\r\nList&lt;Date&gt; dateList = Arrays.asList(d3, d2, d1); \/\/ \u672a\u6765\u2192\u904e\u53bb\u306e\u9806\u306bList\u3092\u4f5c\u3063\u3066\u3001\r\nCollections.sort(dateList); \/\/ List\u3092\u30bd\u30fc\u30c8\u3059\u308b\u3068\r\ndateList.forEach(System.out::println); \/\/ List\u306e\u5185\u5bb9\u304c\u904e\u53bb\u2192\u672a\u6765\u306e\u9806\u306b\u306a\u308b\r\n\r\nDate[] dateArray = { d3, d2, d1 }; \/\/ \u672a\u6765\u2192\u904e\u53bb\u306e\u9806\u306b\u914d\u5217\u3092\u4f5c\u3063\u3066\u3001\r\nArrays.sort(dateArray); \/\/ \u914d\u5217\u3092\u30bd\u30fc\u30c8\u3059\u308b\u3068\r\nArrays.stream(dateArray).forEach(System.out::println); \/\/ \u914d\u5217\u306e\u5185\u5bb9\u304c\u904e\u53bb\u2192\u672a\u6765\u306e\u9806\u306b\u306a\u308b<\/pre>\n<p>\u30d5\u30a3\u30fc\u30eb\u30c9\u3068\u3057\u3066<span>Date<\/span>\u3092\u6301\u3064\u30af\u30e9\u30b9\u306e\u30bd\u30fc\u30c8\u6761\u4ef6\u306b\u3001<span>Date<\/span>\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u52a0\u3048\u305f\u3044\u306a\u3089\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b<span>compareTo<\/span>\u3067\u6307\u5b9a\u3059\u308b\u304b\u3001<span>java.util.Comparator<\/span>\u3092\u4f7f\u3048\u3070\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">import java.util.Date;\r\n\r\nclass DateCompareSample implements Comparable&lt;DateCompareSample&gt; {\r\n\tint intField;\r\n\tDate dateField;\r\n\r\n\tpublic int compareTo(DateCompareSample obj) {\r\n\t\tint ret = Integer.compare(intField, obj.intField);\r\n\r\n\t\tif (ret != 0) {\r\n\t\t\treturn ret;\r\n\t\t}\r\n\r\n\t\treturn dateField.compareTo(obj.dateField);\r\n\t}\r\n}<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">Comparator&lt;DateCompareSample&gt; comparator = new Comparator&lt;DateCompareSample&gt;() {\r\n\tpublic int compare(DateCompareSample obj1, DateCompareSample obj2) {\r\n\t\tint ret = Integer.compare(obj1.intField, obj2.intField);\r\n\r\n\t\tif (ret != 0) {\r\n\t\t\treturn ret;\r\n\t\t}\r\n\r\n\t\treturn obj1.dateField.compareTo(obj2.dateField);\r\n\t}\r\n};<\/pre>\n<h2><span id=\"JavaDate-3\">\uff13\uff0e\u3010Java\u3011Date\u306e\u3044\u308d\u3044\u308d\u306a\u4f7f\u3044\u65b9<\/span><\/h2>\n<p>\u3053\u3053\u3067\u306f\u3001\u5b9f\u969b\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u3067<span>Date<\/span>\u3092\u4f7f\u3046\u5834\u5408\u306b\u3088\u304f\u51fa\u3066\u304f\u308b\u3082\u306e\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<span>Date<\/span>\u306f\u3053\u3046\u3044\u3046\u611f\u3058\u3067\u4f7f\u3048\u307e\u3059\u3088\u3001\u3068\u8a00\u3046\u30b5\u30f3\u30d7\u30eb\u3068\u3057\u3066\u3082\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n<h3><span id=\"i-3\">\uff13-\uff11\uff0e\u30ed\u30b0\u3078\u306e\u65e5\u6642\u306e\u8ffd\u52a0<\/span><\/h3>\n<p>\u3054\u304f\u8eab\u8fd1\u306a\u4f7f\u3044\u65b9\u3068\u3057\u3066\u3001\u30ed\u30b0\u3078\u306e\u65e5\u6642\u3092\u8ffd\u52a0\u3059\u308b\u306e\u306b\u4f7f\u3044\u307e\u3059\u3002\u4f55\u304b\u306e\u51e6\u7406\u306e\u9014\u4e2d\u7d4c\u904e\u3092\u793a\u3059\u30ed\u30b0\u51fa\u529b\u3092\u3059\u308b\u6642\u306b\u3001\u30ed\u30b0\u3092\u51fa\u529b\u3057\u305f\u65e5\u6642\u304c\u3042\u308b\u3053\u3068\u306f\u3001\u30c7\u30d0\u30c3\u30b0\u4e0a\u3068\u3066\u3082\u610f\u5473\u304c\u3042\u308b\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\u3068\u3044\u3063\u3066\u3082\u3084\u308a\u65b9\u306f\u3054\u304f\u7c21\u5358\u3067\u3001\u30ed\u30b0\u306b\u51fa\u3057\u305f\u3044\u6587\u5b57\u5217\u3078<span>Date<\/span>\u3092\u7d50\u5408\u3059\u308c\u3070\u3044\u3044\u3060\u3051\u3067\u3059\u3002\u3054\u304f\u5358\u7d14\u306b\u3084\u308b\u306a\u3089\u4ee5\u4e0b\u306e\u3068\u304a\u308a\u3067\u3059\u3002\u4f8b\u3067\u306f<span>System.out<\/span>\u3092\u4f7f\u3063\u3066\u3044\u307e\u3059\u304c\u3001\u666e\u901a\u306f\u30d5\u30a1\u30a4\u30eb\u306a\u3069\u306e\u51fa\u529b\u30b9\u30c8\u30ea\u30fc\u30e0\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d1 = new Date();\r\nSystem.out.println(d1 + \": \u51e6\u7406XXXX\u304c\u59cb\u307e\u308a\u307e\u3057\u305f\"); \/\/ \u2192 Sat Jun 08 21:34:53 GMT+09:00 2019: \u51e6\u7406XXXX\u304c\u59cb\u307e\u308a\u307e\u3057\u305f\r\n\r\n\/\/ \u4f55\u304b\u306e\u51e6\u7406\r\nfor (long i = 0; i &lt; 10000000000L; i++) {\r\n\t;\r\n}\r\n\r\nDate d2 = new Date();\r\nSystem.out.println(d2 + \": \u51e6\u7406XXXX\u304c\u7d42\u308f\u308a\u307e\u3057\u305f\"); \/\/ \u2192 Sat Jun 08 21:34:56 GMT+09:00 2019: \u51e6\u7406XXXX\u304c\u7d42\u308f\u308a\u307e\u3057\u305f<\/pre>\n<p>\u305f\u3060\u3001\u3053\u308c\u3060\u3068\u3061\u3087\u3063\u3068\u8aad\u307f\u3065\u3089\u3044\u3067\u3059\u3088\u306d\u3002\u3042\u3068\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u3092\u5b9f\u884c\u3059\u308b\u3068\u3001<span>1<\/span>\u79d2\u4ee5\u5185\u3067\u51e6\u7406\u304c\u7d42\u308f\u3063\u3066\u3057\u307e\u3046\u3053\u3068\u3082\u3054\u304f\u666e\u901a\u306a\u306e\u3067\u3001\u305d\u306e\u5834\u5408\u306f\u5b9f\u884c\u72b6\u6cc1\u3092\u628a\u63e1\u3059\u308b\u30ed\u30b0\u3068\u3057\u3066\u306f\u3001\u5c11\u3005\u7269\u8db3\u308a\u306a\u3044\u5185\u5bb9\u3067\u3059\u3002<\/p>\n<p>\u3067\u3059\u304b\u3089\u3001<span>SimpleDateFormat.format<\/span>\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u3001\u4eba\u304c\u8aad\u307f\u3084\u3059\u3044\u5f62\u5f0f\u30fb\u5fc5\u8981\u306a\u65e5\u6642\u306e\u7cbe\u5ea6\u3092\u6301\u3064\u3088\u3046\u3001\u65e5\u6642\u3092\u6587\u5b57\u5217\u306b\u5909\u63db\u3059\u308b\u306e\u304c\u666e\u901a\u3067\u3059\u3002<span>SimpleDateFormat.format<\/span>\u306e\u4f7f\u3044\u65b9\u306f\u3001\u5f8c\u3067\u3054\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"i-4\">\uff13-\uff12\uff0e\u51e6\u7406\u6642\u9593\u306e\u8a08\u6e2c<\/span><\/h3>\n<p>Date\u306f\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u51e6\u7406\u6642\u9593\u3092\u8a08\u6e2c\u3059\u308b\u306e\u306b\u3082\u3088\u304f\u4f7f\u3044\u307e\u3059\u3002<span>Date<\/span>\u306f\u30df\u30ea\u79d2\u307e\u3067\u6301\u3063\u3066\u3044\u307e\u3059\u306e\u3067\u3001\u666e\u901a\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u51e6\u7406\u6642\u9593\u8a08\u6e2c\u306b\u306f\u5341\u5206\u306a\u7cbe\u5ea6\u3067\u3059\u3002<\/p>\n<p>\u3084\u308a\u65b9\u306f\u7c21\u5358\u3067\u3001\u51e6\u7406\u306e\u524d\u5f8c\u3067<span>Date<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3057\u3001\u7d4c\u904e\u6642\u9593\u306e<span>long<\/span>\u5024\u306e\u5f15\u304d\u7b97\u3092\u3059\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date start = new Date(); \/\/ \u51e6\u7406\u958b\u59cb\u65e5\u6642\r\n\r\n\/\/ \u4f55\u304b\u306e\u9577\u3044\u51e6\u7406\r\nfor (long i = 0; i &lt; 10000000000L; i++) {\r\n\t;\r\n}\r\n\r\nDate end = new Date(); \/\/ \u51e6\u7406\u7d42\u4e86\u65e5\u6642\r\nlong diff = end.getTime() - start.getTime(); \/\/ \u51e6\u7406\u7d42\u4e86\u65e5\u6642 - \u51e6\u7406\u958b\u59cb\u65e5\u6642\r\nSystem.out.println(\"\u51e6\u7406\u6642\u9593\u306f \" + diff + \"ms \u3067\u3059\"); \/\/ \u2192 \u51e6\u7406\u6642\u9593\u306f 5019ms \u3067\u3059<\/pre>\n<p>\u3082\u3057\u3001\u30de\u30a4\u30af\u30ed\u79d2\u3084\u30ca\u30ce\u79d2\u5358\u4f4d\u306e\u6e2c\u5b9a\u3092\u3057\u305f\u3044\u306a\u3089\u3001\u6b8b\u5ff5\u306a\u304c\u3089\u30df\u30ea\u79d2\u307e\u3067\u3057\u304b\u6301\u305f\u306a\u3044<span>Date<\/span>\u3067\u306f\u5b9f\u73fe\u3067\u304d\u307e\u305b\u3093\u3002\u305d\u306e\u5834\u5408\u306f\u3001<span>java.time.Instant<\/span>\u306a\u3069\u306e\u3001<span>Java 8<\/span>\u4ee5\u964d\u3067\u4f7f\u3048\u308b\u65b0\u3057\u3044\u30af\u30e9\u30b9\u3092\u4f7f\u3044\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Instant start = Instant.now(); \/\/ \u51e6\u7406\u958b\u59cb\u65e5\u6642\r\n\r\n\/\/ \u4f55\u304b\u306e\u9577\u3044\u51e6\u7406\r\nfor (long i = 0; i &lt; 10000000000L; i++) {\r\n\t;\r\n}\r\n\r\nInstant end = Instant.now(); \/\/ \u51e6\u7406\u7d42\u4e86\u65e5\u6642\r\n\/\/ \u51e6\u7406\u7d42\u4e86\u65e5\u6642 - \u51e6\u7406\u958b\u59cb\u65e5\u6642(\u30ca\u30ce\u79d2\u5358\u4f4d)\r\nlong diff = (end.getEpochSecond() * 1000000000 + end.getNano())\r\n\t\t- (start.getEpochSecond() * 1000000000 + start.getNano());\r\nSystem.out.println(\"\u51e6\u7406\u6642\u9593\u306f \" + diff + \"ns \u3067\u3059\"); \/\/ \u2192 \u51e6\u7406\u6642\u9593\u306f 5014588300ns \u3067\u3059<\/pre>\n<h3><span id=\"i-5\">\uff13-\uff13\uff0e\u7279\u5b9a\u671f\u9593\u306e\u52a0\u7b97\u30fb\u6e1b\u7b97<\/span><\/h3>\n<p>\u7e70\u308a\u8fd4\u3057\u3067\u3059\u304c\u3001<span>Date<\/span>\u306f\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u3057\u304b\u6301\u3063\u3066\u3044\u307e\u305b\u3093\u3002\u305d\u306e\u6a5f\u80fd\u3057\u304b\u306a\u3044\u30af\u30e9\u30b9\u3067\u3059\u3002\u3067\u3059\u304b\u3089\u3001\u7279\u5b9a\u671f\u9593<span>\u2026<\/span>\u3064\u307e\u308a\u5206\u30fb\u6642\u9593\u30fb\u65e5\u30fb\u5e74\u306a\u3069\u306e\u52a0\u6e1b\u7b97\u304c\u3067\u304d\u308b\u76f4\u63a5\u7684\u306a\u30e1\u30bd\u30c3\u30c9\u306f\u6301\u3063\u3066\u3044\u307e\u305b\u3093\u3002<\/p>\n<p>Date\u3060\u3051\u3067\u305d\u306e\u3088\u3046\u306a\u3053\u3068\u3092\u3084\u308b\u306a\u3089\u3001\u7d4c\u904e\u6642\u9593\u3078\u306e\u52a0\u7b97\u30fb\u6e1b\u7b97\u3092\u884c\u3063\u3066\u3001\u305d\u306e\u7d4c\u904e\u6642\u9593\u304b\u3089\u65b0\u3057\u3044<span>Date<\/span>\u3092\u4f5c\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u8a08\u7b97\u3092\u3059\u308b\u6642\u306f\u3001\u7d4c\u904e\u6642\u9593\u306f\u30df\u30ea\u79d2\u3060\u3068\u3044\u3046\u3053\u3068\u3092\u610f\u8b58\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/01\/01 00:00:00.000\"); \/\/ 2019\/1\/1\u306eDate\u3092\u4f5c\u3063\u3066\u3001\r\nlong time = d.getTime(); \/\/ \u7d4c\u904e\u6642\u9593\u3092\u53d6\u5f97\u3057\u3066\u3001\r\n\r\n\/\/ \u5206\u30fb\u6642\u9593\u30fb\u65e5\u30fb\u6708\u30fb\u5e74\u306e\u7d4c\u904e\u6642\u9593\u3092\u30df\u30ea\u79d2\u5358\u4f4d\u3067\u8a08\u7b97\u3057\u3066\u3001\r\nlong min = 1000 * 60;\r\nlong hour = min * 60;\r\nlong day = hour * 24;\r\nlong month = day * 31;\r\nlong year = day * 365;\r\n\r\n\/\/ \u305d\u308c\u305e\u308c\u8db3\u3057\u5408\u308f\u305b\u308b\u3068\u3001\u65e5\u6642\u304c\u9032\u3093\u3067\u3044\u308bDate\u3092\u4f5c\u308c\u308b\r\nSystem.out.println(d); \/\/ \u2192 Tue Jan 01 00:00:00 GMT+09:00 2019\r\nSystem.out.println(new Date(time + min)); \/\/ \u2192 Tue Jan 01 00:01:00 GMT+09:00 2019\r\nSystem.out.println(new Date(time + hour)); \/\/ \u2192 Tue Jan 01 01:00:00 GMT+09:00 2019\r\nSystem.out.println(new Date(time + day)); \/\/ \u2192 Wed Jan 02 00:00:00 GMT+09:00 2019\r\nSystem.out.println(new Date(time + month)); \/\/ \u2192 Fri Feb 01 00:00:00 GMT+09:00 2019\r\nSystem.out.println(new Date(time + year)); \/\/ \u2192 Wed Jan 01 00:00:00 GMT+09:00 2020<\/pre>\n<p>\u305f\u3060\u3057\u3001\u3053\u308c\u306f\u5358\u306b\u6a5f\u68b0\u7684\u306b\u8a08\u7b97\u3057\u305f\u7d50\u679c\u3067\u3057\u304b\u3042\u308a\u307e\u305b\u3093\u3002\u4f8b\u3048\u3070\u4f55\u304b\u306e<span>Date<\/span>\u3092\u7fcc\u6708<span>1<\/span>\u65e5\u306b\u3059\u308b\u3001\u3068\u3044\u3046\u3088\u3046\u306a\u51e6\u7406\u306f\u306a\u304b\u306a\u304b\u306b\u5927\u5909\u3067\u3059\u3002\u306a\u305c\u306a\u3089\u3001\u5b9f\u969b\u306b\u306f\u6708\u3054\u3068\u306e\u65e5\u6570\u3084\u958f\u5e74\u3092\u8003\u616e\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u305d\u3093\u306a\u3053\u3068\u3092\u3084\u308b\u305f\u3081\u306b\u3001<span>Date<\/span>\u3068\u306f\u5225\u306b<span>java.util.Calendar<\/span>\u304c\u3042\u308a\u307e\u3059\u3002<span>Calendar<\/span>\u306e\u7c21\u5358\u306a\u4f7f\u3044\u65b9\u3068\u3001<span>Date<\/span>\u3068\u306e\u9023\u643a\u306e\u3055\u305b\u65b9\u306f\u3001\u5f8c\u306e\u7ae0\u3067\u3082\u3054\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-DateInstant\">\uff13-\uff14\uff0e\u3010\u53c2\u8003\u3011Date\u304b\u3089Instant\u3092\u53d6\u5f97\u3059\u308b<\/span><\/h3>\n<p>Date.from\u3067\u306fInstant\u304b\u3089Date\u3092\u4f5c\u308c\u307e\u3059\u304c\u3001\u9006\u306bDate.toInstant\u3067\u306fDate\u304b\u3089Instant\u3092\u4f5c\u308c\u307e\u3059\u3002Date\u306f\u30df\u30ea\u79d2\u307e\u3067\u3067\u3059\u306e\u3067\u3001\u5f53\u7136\u4f5c\u3063\u305f<span>Instant<\/span>\u306e\u30de\u30a4\u30af\u30ed\u79d2\u30fb\u30ca\u30ce\u79d2\u306f<span>0<\/span>\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSSXXX\");\r\nDate d = df.parse(\"2019\/01\/01 00:00:00.000+00:00\");\r\nInstant i = d.toInstant();\r\nSystem.out.println(i); \/\/ \u2192 2019-01-01T00:00:00Z<\/pre>\n<h2><span id=\"CalendarSimpleDateFormat\">\uff14\uff0eCalendar\/SimpleDateFormat\u3068\u306e\u9023\u643a<\/span><\/h2>\n<p>Date\u3092\u4f7f\u3046\u6642\u306f\u3001java.util.Calendar\u3068java.text.SimpleDateFormat\u3068\u7d44\u307f\u5408\u308f\u305b\u308b\u3053\u3068\u304c\u5927\u5909\u591a\u3044\u3067\u3059\u3002\u3053\u308c\u3089\u306e\u30af\u30e9\u30b9\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u3088\u304f\u3084\u308b\u3053\u3068\u3092\u3001\u3044\u304f\u3064\u304b\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-DateCalendarCalendarDate\">\uff14-\uff11\uff0e\u3010\u91cd\u8981\u3011Date\u3092Calendar\u306b\u3059\u308b\/Calendar\u3092Date\u306b\u3059\u308b<\/span><\/h3>\n<p>\u307e\u305a\u3001Calendar\u3068Date\u3092\u9023\u643a\u3055\u305b\u308b\u305f\u3081\u306b\u3001Date\u2192Calendar\u3001Calendar\u2192Date\u306e\u5909\u63db\u306e\u4ed5\u65b9\u3092\u899a\u3048\u307e\u3057\u3087\u3046\u3002\u3068\u3044\u3063\u3066\u3082\u3001\u4eca\u307e\u3067\u306e\u4f8b\u3067\u3082\u51fa\u3066\u304d\u3066\u3044\u307e\u3059\u306d\u3002\u4ee5\u4e0b\u306e\u3088\u3046\u306bCalendar.getTime\/setTime\u3067\u884c\u3044\u307e\u3059\u3002<\/p>\n<p><strong><span class=\"f-marker-p\">Date\u2192Calendar\uff1a<\/span><\/strong><\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date();\r\nCalendar c = Calendar.getInstanct();\r\nc.setTime(d);<\/pre>\n<p><strong><span class=\"f-marker-y\">Calendar\u2192Date\uff1a<\/span><\/strong><\/p>\n<pre class=\"prettyprint lang:default decode:true\">Calendar c = Calendar.getInstanct();\r\nDate d = c.getTime();<\/pre>\n<p>\u306a\u304a\u3001<span>Calendar<\/span>\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306f<span>new<\/span>\u3067\u306f\u4f5c\u308c\u307e\u305b\u3093\u3002<span>Calendar.getInstance<\/span>\u3067\u73fe\u5728\u65e5\u6642\u306e<span>Calendar<\/span>\u3092\u53d6\u5f97\u3057\u3001\u305d\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306b\u3044\u308d\u3044\u308d\u3068\u8a2d\u5b9a\u3057\u3066\u3044\u304f\u5f62\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<h3><span id=\"-SimpleDateFormatDate\">\uff14-\uff12\uff0e\u3010\u91cd\u8981\u3011SimpleDateFormat\u3067\u3001Date\u3092\u6587\u5b57\u5217\u3068\u3057\u3001\u89e3\u6790\u3092\u3059\u308b<\/span><\/h3>\n<p>Date\u306e\u4f5c\u308a\u65b9\u306e\u3068\u3053\u308d\u3067\u3001SimpleDateFormat.parse\u3092\u4f7f\u3063\u3066\u3001\u6587\u5b57\u5217\u304b\u3089Date\u3092\u4f5c\u308a\u307e\u3057\u305f\u3002\u305d\u306e\u9006\u3001\u3064\u307e\u308a<span>Date<\/span>\u304b\u3089\u6587\u5b57\u5217\u3092\u4f5c\u308b\u306b\u306f\u3001<span>SimpleDateFormat.format<\/span>\u3092\u4f7f\u3044\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date();\r\n\r\n\/\/ YYYY\/MM\/DD HH:MM.SS.SSS\u5f62\u5f0f\u306eSimpleDateFormat\u3092\u4f5c\u3063\u3066\u3001\r\nSimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\n\/\/ Date\u3092\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u3057\u305f\u6587\u5b57\u5217\u3092\u4f5c\u308b\r\nString dateStr = df.format(d);\r\n\r\nSystem.out.println(dateStr); \/\/ \u2192 2019\/06\/08 21:51:25.710\u3001\u6307\u5b9a\u3057\u305f\u66f8\u5f0f\u306e\u51fa\u529b\u306b\u306a\u308b\r\nSystem.out.println(d); \/\/ \u2192 Sat Jun 08 21:51:25 GMT+09:00 2019\u3001Date\u306f\u540c\u3058\u65e5\u6642\u3067\u3042\u308b\r\n\r\nDate d2 = df.parse(dateStr); \/\/ \u540c\u3058SimpleDateFormat\u3067\u6587\u5b57\u5217\u3092parse\u3059\u308b\u3068\u3001\r\nSystem.out.println(d2); \/\/ \u2192 Sat Jun 08 21:51:25 GMT+09:00 2019\u3001\u540c\u3058\u65e5\u6642\u306eDate\u306b\u306a\u308b<\/pre>\n<p>\u3053\u306e\u3088\u3046\u306b\u3001<span>SimpleDateFormat<\/span>\u306f\u3001\u6587\u5b57\u5217\u306e\u89e3\u6790\u3068\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u306e\u4e21\u65b9\u306b\u4f7f\u3048\u308b\u5927\u5909\u4fbf\u5229\u306a\u30af\u30e9\u30b9\u306a\u306e\u3067\u3059\u3002<\/p>\n<h4>\uff14-\uff12-\uff11\uff0eSimpleDateFormat\u3067\u3088\u304f\u4f7f\u3046\u66f8\u5f0f\u6587\u5b57\u5217<\/h4>\n<p>SimpleDateFormat\u3067\u3088\u304f\u4f7f\u3046\u66f8\u5f0f\u6587\u5b57\u5217\u306f\u4ee5\u4e0b\u306e\u3082\u306e\u3067\u3059\u3002\u66f8\u5f0f\u6587\u5b57\u5217\u3067\u306f\u3001\u7279\u5b9a\u306e\u30a2\u30eb\u30d5\u30a1\u30d9\u30c3\u30c8\u304a\u3088\u3073\u305d\u306e\u6570\u304c\u66f8\u5f0f\u4e0a\u3067\u610f\u5473\u3092\u6301\u3061\u307e\u3059\u3002\u66f8\u5f0f\u6587\u5b57\u5217\u306e\u8a73\u7d30\u306f\u3001SimpleDateFormat\u306eJavadoc\u3067\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<ul>\n<li>yyyy \u2192 \u5e74(year)\u306e4\u68410\u57cb\u3081\u8868\u73fe(0000\uff5e9999)\u3001\u4f8b:2019<\/li>\n<li>MM \u2192 \u6708(Month)\u306e2\u68410\u57cb\u3081\u8868\u73fe(01\uff5e12)\u3001\u4f8b:01\u300112<\/li>\n<li>dd \u2192 \u65e5(day)\u306e2\u68410\u57cb\u3081\u8868\u73fe(00\uff5e31)\u3001\u4f8b:09\u300131<\/li>\n<li>HH \u2192 \u6642(Hour)\u306e24\u6642\u9593\u8868\u8a18\u306e2\u68410\u57cb\u3081\u8868\u73fe(00\uff5e23)\u3001\u4f8b: 03\u300112\u300123<\/li>\n<li>mm \u2192 \u5206(minute)\u306e2\u68410\u57cb\u3081\u8868\u73fe(00\uff5e59)\u3001\u4f8b: 00\u300109\u300130\u300155<\/li>\n<li>ss \u2192 \u79d2(second)\u306e2\u68410\u57cb\u3081\u8868\u73fe(00\uff5e59)\u3001\u4f8b: 01\u300110\u300145\u300159<\/li>\n<li><span>SSS \u2192 <\/span>\u30df\u30ea\u79d2\u306e<span>3<\/span>\u6841<span>0<\/span>\u57cb\u3081\u8868\u73fe<span>(000<\/span>\uff5e<span>999)<\/span>\u3001\u4f8b<span>: 008<\/span>\u3001<span>012<\/span>\u3001<span>123<\/span><\/li>\n<li><span>XXX \u2192 <\/span>\u6642\u5dee\u306e\u8868\u73fe\u3001<span>+HH:mm<\/span>\u3084<span>-HH:mm<\/span>\u5f62\u5f0f\u306e\u6587\u5b57\u5217\u306a\u3069\u3001\u4f8b<span>: +09:00<\/span>\u3001<span>-09:30<\/span><\/li>\n<\/ul>\n<p>\u3053\u308c\u4ee5\u5916\u306e\u30a2\u30eb\u30d5\u30a1\u30d9\u30c3\u30c8\u3082\u610f\u5473\u3092\u6301\u3061\u307e\u3059\u304c\u3001\u66f8\u5f0f\u3068\u3057\u3066\u306f\u4f7f\u308f\u305a\u3001\u5358\u306b\u6587\u5b57\u5217\u3068\u3057\u3066\u51fa\u529b\u306b\u6df7\u305c\u8fbc\u307f\u305f\u3044\u306a\u3089<span>&#8221;<\/span>\u3067\u304f\u304f\u308a\u307e\u3059\u3002\u30a2\u30eb\u30d5\u30a1\u30d9\u30c3\u30c8\u4ee5\u5916\u306e\u6587\u5b57<span>(\/<\/span>\u3001<span>&#8211;<\/span>\u3001\u7a7a\u767d\u306a\u3069<span>)<\/span>\u306f\u304f\u304f\u308b\u5fc5\u8981\u306f\u306a\u304f\u3001\u305d\u306e\u307e\u307e\u66f8\u3051\u307e\u3059\u3002<\/p>\n<p>\u306a\u304a\u3001\u89e3\u6790\u3059\u308b\u6587\u5b57\u5217\u304c\u66f8\u5f0f\u6587\u5b57\u5217\u3069\u304a\u308a\u3067\u3042\u308c\u3070\u89e3\u6790\u3067\u304d\u308b\u306e\u3067\u3001\u6b27\u7c73\u306a\u3069\u3067\u3088\u304f\u898b\u3089\u308c\u308b<span>MM\/dd\/yyyy<\/span>\u5f62\u5f0f\u306a\u3069\u306b\u5bfe\u5fdc\u3057\u305f\u3044\u306a\u3089\u3001\u305d\u306e\u3068\u304a\u308a\u306b\u66f8\u5f0f\u6587\u5b57\u5217\u3092\u4f5c\u308c\u3070<span>OK<\/span>\u3067\u3059\u3002<\/p>\n<h3><span id=\"-Date-6\">\uff14-\uff13\uff0eDate\u304b\u3089\u5e74\u6708\u65e5\u30fb\u6642\u523b\u30fb\u66dc\u65e5\u306a\u3069\u3092\u62bd\u51fa\u3059\u308b<\/span><\/h3>\n<p>\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u3057\u304b\u6301\u3063\u3066\u3044\u306a\u3044<span>Date<\/span>\u3060\u3051\u3067\u306f\u3001\u5e74\u6708\u65e5\u30fb\u6642\u5206\u79d2\u30fb\u66dc\u65e5\u306e\u62bd\u51fa\u3092\u3059\u308b\u306e\u306f\u96e3\u3057\u3044\u3067\u3059\u3002\u3082\u3061\u308d\u3093\u3001\u8a08\u7b97\u3059\u308c\u3070\u3067\u304d\u306a\u3044\u3053\u3068\u306f\u3042\u308a\u307e\u305b\u3093\u304c\u3001\u7d50\u69cb\u306a\u91cf\u306e\u8a08\u7b97\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n<p>\u3053\u306e\u5834\u5408\u306f\u3001<span>Calendar<\/span>\u3042\u308b\u3044\u306f<span>SimpleDateFormat<\/span>\u306a\u3069\u3092\u4f7f\u3063\u3066\u3001\u4e00\u5fdc\u306f\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5fc5\u8981\u306a\u60c5\u5831\u3092\u629c\u304d\u51fa\u3059\u3053\u3068\u306f\u3067\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/01\/02 12:34:56.789\");\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\nint year = c.get(Calendar.YEAR);\r\nint month = c.get(Calendar.MONTH);\r\nint day = c.get(Calendar.DAY_OF_MONTH);\r\nint hour = c.get(Calendar.HOUR_OF_DAY);\r\nint min = c.get(Calendar.MINUTE);\r\nint sec = c.get(Calendar.SECOND);\r\nint ms = c.get(Calendar.MILLISECOND);\r\nint weekday = c.get(Calendar.DAY_OF_WEEK);\r\n\r\nSystem.out.println(year); \/\/ \u2192 2019\r\nSystem.out.println(month); \/\/ \u2192 0 (Calendar\u3067\u306f\u6708\u306f0\u59cb\u307e\u308a\u306e\u305f\u3081\u30011\u6708\u306f0\u306b\u306a\u308b)\r\nSystem.out.println(day); \/\/ \u2192 2\r\nSystem.out.println(hour); \/\/ \u2192 12\r\nSystem.out.println(min); \/\/ \u2192 34\r\nSystem.out.println(sec); \/\/ \u2192 56\r\nSystem.out.println(ms); \/\/ \u2192 789\r\nSystem.out.println(weekday); \/\/ \u2192 4 (2019\/1\/2\u306f\u6c34\u66dc\u65e5\u3001Calendar\u3067\u306f4\u304c\u623b\u308b(\u65e5\u66dc\u65e5\u304c1))<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/01\/02 12:34:56.789\");\r\n\r\nSimpleDateFormat df1 = new SimpleDateFormat(\"yyyy\");\r\nSimpleDateFormat df2 = new SimpleDateFormat(\"MM\");\r\nSimpleDateFormat df3 = new SimpleDateFormat(\"dd\");\r\nSimpleDateFormat df4 = new SimpleDateFormat(\"HH\");\r\nSimpleDateFormat df5 = new SimpleDateFormat(\"mm\");\r\nSimpleDateFormat df6 = new SimpleDateFormat(\"ss\");\r\nSimpleDateFormat df7 = new SimpleDateFormat(\"SSS\");\r\nSimpleDateFormat df8 = new SimpleDateFormat(\"u\");\r\n\r\nSystem.out.println(df1.format(d)); \/\/ \u2192 \"2019\"\r\nSystem.out.println(df2.format(d)); \/\/ \u2192 \"01\"\r\nSystem.out.println(df3.format(d)); \/\/ \u2192 \"02\"\r\nSystem.out.println(df4.format(d)); \/\/ \u2192 \"12\"\r\nSystem.out.println(df5.format(d)); \/\/ \u2192 \"34\"\r\nSystem.out.println(df6.format(d)); \/\/ \u2192 \"56\"\r\nSystem.out.println(df7.format(d)); \/\/ \u2192 \"789\"\r\nSystem.out.println(df8.format(d)); \/\/ \u2192 \"3\" (1\u306e\u6708\u66dc\u65e5\u304b\u3089\u59cb\u307e\u308b)<\/pre>\n<h3><span id=\"-Date-7\">\uff14-\uff14\uff0eDate\u304b\u3089\u306e\u6708\u672b\u6708\u521d\u3092\u8a08\u7b97\u3059\u308b<\/span><\/h3>\n<p>\u6708\u672b\u6708\u521d\u306e\u8a08\u7b97\u3068\u306f\u3001\u4f8b\u3048\u3070<span> 2019\/06\/10 12:34:56.789<\/span>\u3068\u3044\u3046\u65e5\u6642\u304b\u3089\u3001\u6708\u672b\u3068\u6708\u521d\u306e\u65e5\u4ed8\u304c\u3044\u3064\u304b\u3092\u8abf\u3079\u308b\u3053\u3068\u3067\u3059\u3002\u4f8b\u3067\u306f\u3001\u6708\u672b\u306f<span>2019\/6\/30<\/span>\u3067\u3001\u6708\u521d\u306f<span>2019\/6\/1<\/span>\u3067\u3059\u3002<\/p>\n<p>\u666e\u901a\u306e\u6708\u306a\u3089\u3001\u6708\u672b\u306f\u6708\u3092\u898b\u308c\u3070<span>30\/31<\/span>\u65e5\u3092\u5224\u65ad\u3067\u304d\u307e\u3059\u304c\u3001<span>2<\/span>\u6708\u306f\u3046\u308b\u3046\u5e74\u3067<span>28\/29<\/span>\u65e5\u304c\u9055\u3044\u307e\u3059\u3088\u306d\u3002\u305d\u306e\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306f\u5c11\u3005\u9762\u5012\u3067\u3059\u3057\u3001\u5b9f\u306f\u3046\u308b\u3046\u5e74\u306e\u6b63\u3057\u3044\u8a08\u7b97\u65b9\u6cd5\u3092\u77e5\u3089\u306a\u3044\u4eba\u3082\u3044\u3066\u3001\u5371\u306a\u3063\u304b\u3057\u3044\u3067\u3059\u3002<\/p>\n<p>\u3053\u306e\u3088\u3046\u306a\u51e6\u7406\u306f\u3001Date\u304b\u3089Calendar\u3092\u4f5c\u308a\u3001Calendar.getActualMaximum\u200b\/getActualMinimum\u3092\u4f7f\u3046\u3053\u3068\u3067\u7c21\u5358\u306b\u884c\u3048\u307e\u3059\u3002\u3053\u308c\u3089\u306f\u3001<span>Calendar<\/span>\u304c\u6301\u3064\u30d5\u30a3\u30fc\u30eb\u30c9\u3067\u3001\u3042\u308a\u5f97\u308b\u5024\u306e\u6700\u5927\u30fb\u6700\u5c0f\u5024\u3092\u623b\u3059\u30e1\u30bd\u30c3\u30c9\u3067\u3059<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/06\/10 12:34:56.789\");\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\n\r\n\/\/ \u30d5\u30a3\u30fc\u30eb\u30c9DAY_OF_MONTH(\u65e5)\u304c\u53d6\u308a\u5f97\u308b\u3001\u6700\u5927\u5024\u3068\u6700\u5c0f\u5024\u3092\u53d6\u5f97\u3059\u308b\r\nSystem.out.println(c.getActualMaximum(Calendar.DAY_OF_MONTH)); \/\/ \u2192 30\r\nSystem.out.println(c.getActualMinimum(Calendar.DAY_OF_MONTH)); \/\/ \u2192 1<\/pre>\n<p>\u5f53\u7136\u306a\u304c\u3089\u3001\u3046\u308b\u3046\u5e74\u3092\u610f\u8b58\u3057\u305f\u51e6\u7406\u3082\u304d\u3061\u3093\u3068\u3057\u3066\u304f\u308c\u307e\u3059\u3088\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2000\/02\/10 12:34:56.789\");\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\n\r\n\/\/ 2000\u5e74\u306f\u3046\u308b\u3046\u5e74\u306a\u306e\u3067\u30012\u6708\u306e\u6708\u672b\u306f29\u65e5\u306b\u306a\u308b\r\nSystem.out.println(c.getActualMaximum(Calendar.DAY_OF_MONTH)); \/\/ \u2192 29\r\nSystem.out.println(c.getActualMinimum(Calendar.DAY_OF_MONTH)); \/\/ \u2192 1<\/pre>\n<h3><span id=\"-0Date\">\uff14-\uff15\uff0e\u30b8\u30e3\u30b9\u30c8<span>0<\/span>\u5206\u306a\u3069\u306b\u65e5\u6642\u3092\u5207\u308a\u6368\u3066\u30fb\u5207\u308a\u4e0a\u3052\u3057\u305f<span>Date<\/span>\u3092\u4f5c\u308b<\/span><\/h3>\n<p>Date\u306f\u30df\u30ea\u79d2\u307e\u3067\u306e\u65e5\u6642\u3092\u6301\u3063\u3066\u3044\u307e\u3059\u304c\u3001\u30df\u30ea\u79d2\u306f\u4e0d\u8981\u3060\u3063\u305f\u308a\u3001\u65e5\u4ed8\u306f\u305d\u306e\u307e\u307e\u306b<span>0<\/span>\u6642<span>0<\/span>\u5206<span>0<\/span>\u79d2\u306b\u3057\u305f\u3044\u3053\u3068\u3082\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u4ed6\u306b\u3082\u3001\u6b21\u306e\u79d2\u3084\u5206\u306b\u9032\u3081\u305f\u3044\u6642\u3082\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u305d\u306e\u5834\u5408\u3082\u3001<span>Calendar<\/span>\u306a\u3069\u3067\u3067\u304d\u307e\u3059\u3002<\/p>\n<h4>\uff14-\uff15-\uff11\uff0e\u5207\u308a\u6368\u3066<\/h4>\n<p>Date\u3092\u4e00\u65e6<span>Calendar<\/span>\u306b\u5909\u63db\u3057\u3001\u5207\u308a\u6368\u3066\u3057\u305f\u3044\u30d5\u30a3\u30fc\u30eb\u30c9\u4ee5\u4e0b\u3078\u3001<span>Calendar.set<\/span>\u3067<span>0<\/span>\u3092\u8a2d\u5b9a\u3057\u307e\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001<span>0<\/span>\u6642<span>0<\/span>\u5206\u30b8\u30e3\u30b9\u30c8\u306b\u3057\u305f\u3044\u306a\u3089\u3001<span>Calendar<\/span>\u306e\u6642\u30fb\u5206\u30fb\u79d2\u30fb\u30df\u30ea\u79d2\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3092<span>0<\/span>\u306b\u3057\u307e\u3059\u3002\u5206\u4ee5\u4e0b\u3001\u79d2\u4ee5\u4e0b\u306a\u3089\u3001\u305d\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u304b\u3089\u306b\u3059\u308c\u3070<span>OK<\/span>\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/06\/06 12:34:56.789\");\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\n\r\n\/\/ \u6642\u30fb\u5206\u30fb\u79d2\u30fb\u30df\u30ea\u79d2\u30920\u306b\u3059\u308b\r\nc.set(Calendar.HOUR_OF_DAY, 0);\r\nc.set(Calendar.MINUTE, 0);\r\nc.set(Calendar.SECOND, 0);\r\nc.set(Calendar.MILLISECOND, 0);\r\n\r\nDate d2 = c.getTime();\r\nSystem.out.println(d2); \/\/ \u2192 Thu Jun 06 00:00:00 GMT+09:00 2019\u30010\u66420\u52060\u79d2\u306b\u306a\u3063\u305f<\/pre>\n<p>\u3042\u308b\u3044\u306f\u3001\u4e00\u65e6\u6587\u5b57\u5217\u306b\u5909\u63db\u3057\u3066\u89e3\u6790\u3057\u76f4\u3059\u3001\u3068\u3044\u3046\u624b\u3082\u4f7f\u3048\u306a\u3044\u3053\u3068\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u66f8\u5f0f\u6587\u5b57\u5217\u306b\u542b\u307e\u308c\u3066\u3044\u306a\u3044\u30d5\u30a3\u30fc\u30eb\u30c9\u306f<span>0<\/span>\u306b\u306a\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/06\/06 12:34:56.789\");\r\n\r\n\/\/ \u6642\u5206\u79d2\u30920\u306b\u3059\u308b\u306e\u3067\u3001\u5e74\u6708\u65e5\u3060\u3051\u306e\u6587\u5b57\u5217\u306b\u4e00\u65e6\u3057\u3066\u3001\r\nSimpleDateFormat df2 = new SimpleDateFormat(\"yyyyMMdd\");\r\nString dateStr = df2.format(d);\r\n\/\/ \u305d\u306e\u5e74\u6708\u65e5\u306e\u6587\u5b57\u5217\u3092\u518d\u5ea6parse\u3059\u308c\u3070\u3001\r\nDate d2 = df2.parse(dateStr);\r\nSystem.out.println(d2); \/\/ \u2192 Thu Jun 06 00:00:00 GMT+09:00 2019\u30010\u66420\u52060\u79d2\u306b\u306a\u3063\u305f<\/pre>\n<p>\u306a\u304a\u3001\u30df\u30ea\u79d2\u3060\u3051\u3044\u3089\u306a\u3044\u306a\u3089\u3001\u7d4c\u904e\u6642\u9593\u306e\u30df\u30ea\u79d2\u3092<span>1000<\/span>\u3067\u5272\u3063\u3066\u3001\u307e\u305f<span>1000<\/span>\u3092\u639b\u3051\u308b\u3068\u3044\u3046\u3001\u304a\u624b\u8efd\u306a\u8a08\u7b97\u3067\u306e\u624b\u6bb5\u3082\u4e00\u5fdc\u3067\u304d\u307e\u3059\u3002\u4f7f\u3046\u6a5f\u4f1a\u306f\u306a\u3044\u3068\u601d\u3044\u307e\u3059\u304c<span>\u2026<\/span>\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/06\/06 12:34:56.789\");\r\nlong time = (long)(d.getTime() \/ 1000) * 1000;\r\nDate d2 = new Date(time);\r\nSystem.out.println(df.format(d2)); \/\/ \u2192 2019\/06\/06 12:34:56.000<\/pre>\n<h4>\uff14-\uff15-\uff12\uff0e\u5207\u308a\u4e0a\u3052<\/h4>\n<p>\u3044\u308d\u3044\u308d\u3068\u65b9\u6cd5\u306f\u3042\u308a\u307e\u3059\u304c\u3001\u305b\u3063\u304b\u304f\u5207\u308a\u6368\u3066\u3092\u7d39\u4ecb\u3057\u307e\u3057\u305f\u306e\u3067\u3001\u305d\u308c\u3092\u6d3b\u7528\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u3064\u307e\u308a\u3001\u5207\u308a\u4e0a\u3052\u3057\u305f\u3044\u30d5\u30a3\u30fc\u30eb\u30c9\u672a\u6e80\u3092\u5207\u308a\u6368\u3066\u3057\u305f\u5f8c\u306b\u3001\u5bfe\u8c61\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u3092<span>Calendar.add<\/span>\u3067<span>+1<\/span>\u3057\u307e\u3059\u3002<\/p>\n<p>\u4ee5\u4e0b\u306e\u4f8b\u3067\u306f\u3001\u79d2\u3092\u5207\u308a\u4e0a\u3052\u3057\u3066\u3001\u6b21\u306e\u5206\u306b\u3057\u3066\u3044\u307e\u3059\u3002\u3082\u3057<span>59<\/span>\u5206\u3060\u3063\u305f\u3068\u3059\u308c\u3070\u3001\u5206\u3092<span>+1<\/span>\u3059\u308c\u3070\u3001\u6642\u9593\u3082\u5f53\u7136\u81ea\u52d5\u7684\u306b<span>+1<\/span>\u3055\u308c\u307e\u3059\u3002\u6587\u5b57\u5217\u64cd\u4f5c\u3060\u3068\u3001\u3053\u3046\u306f\u7c21\u5358\u306b\u306f\u3044\u304d\u307e\u305b\u3093\u306d\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">SimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nDate d = df.parse(\"2019\/06\/06 12:34:56.789\");\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\n\r\n\/\/ \u79d2\u306e\u5358\u4f4d\u3067\u5207\u308a\u4e0a\u3052\u3059\u308b\u306e\u3067\u3001\u79d2\u30fb\u30df\u30ea\u79d2\u30920\u306b\u3057\u3066\u3001\r\nc.set(Calendar.SECOND, 0);\r\nc.set(Calendar.MILLISECOND, 0);\r\n\/\/ \u305d\u306e\u5f8c\u3001\u5206\u3092+1\u3059\u308b\r\nc.add(Calendar.MINUTE, 1);\r\n\r\nDate d2 = c.getTime();\r\nSystem.out.println(d2); \/\/ \u2192 Thu Jun 06 12:35:00 GMT+09:00 2019\u300135\u5206\u306b\u306a\u3063\u305f<\/pre>\n<p>\u306a\u304a\u3001\u672c\u6765\u306e\u5207\u308a\u4e0a\u3052\u51e6\u7406\u306a\u3089\u3001\u3053\u306e\u4f8b\u3060\u3068\u79d2\u304b\u30df\u30ea\u79d2\u304c<span>1<\/span>\u4ee5\u4e0a\u304b\u3092\u30c1\u30a7\u30c3\u30af\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u3067\u3057\u3087\u3046\u3002\u305d\u306e\u30c1\u30a7\u30c3\u30af\u51e6\u7406\u306e\u8ffd\u52a0\u306f\u3001\u7686\u3055\u3093\u3078\u304a\u4efb\u305b\u3057\u307e\u3059\u3002<\/p>\n<p>\u307e\u305f\u3001<span>Calendar.add<\/span>\u3067\u30de\u30a4\u30ca\u30b9\u306e\u6570\u5024\u3092\u6307\u5b9a\u3059\u308c\u3070\u3001\u305d\u306e\u5206\u3060\u3051\u5bfe\u8c61\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u524d\u306b\u306a\u308a\u307e\u3059\u3002\u305d\u3057\u3066\u3001\u5e74\u6708\u65e5\u3078\u3082\u5f53\u7136\u4f7f\u3048\u307e\u3059\u306e\u3067\u3001\u4fbf\u5229\u306b\u4f7f\u3063\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<h3><span id=\"i-6\">\uff14-\uff16\uff0e\u3010\u91cd\u8981\u3011\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u610f\u8b58\u3057\u305f\u51e6\u7406\u3092\u3059\u308b<\/span><\/h3>\n<p>\u3053\u3053\u307e\u3067\u305a\u3063\u3068\u304a\u8a71\u3057\u3066\u304d\u305f\u901a\u308a\u3001<span>Date<\/span>\u306f\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u3092\u6301\u3063\u3066\u3044\u308b\u30af\u30e9\u30b9\u3067\u3059\u3002<span>Date<\/span>\u306e\u57fa\u6e96\u65e5\u6642\u306f<span>GMT<\/span>\u3001\u3044\u308f\u3086\u308b\u5354\u5b9a\u4e16\u754c\u6642\u306e<span>UTC+0<\/span>\u3067\u3001\u3069\u3053\u304b\u5225\u306e\u5730\u57df\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n<p>Date\u81ea\u8eab\u304c\u6301\u3063\u3066\u3044\u308b\u65e5\u6642\u306f<span>GMT<\/span>\u3067\u3059\u3002\u4eca\u307e\u3067\u306e\u4f8b\u3067\u3001<span>Date<\/span>\u3092<span>print<\/span>\u3057\u305f\u6642\u306b<span>&#8220;GMT+09:00&#8221;<\/span>\u304c\u4e00\u7dd2\u306b\u51fa\u3066\u3044\u307e\u3059\u304c\u3001\u3053\u308c\u306f\u79c1\u306e\u30d1\u30bd\u30b3\u30f3\u306e\u74b0\u5883\u304c\u65e5\u672c\u6642\u9593<span>(UTC+9)<\/span>\u3067\u3001\u5358\u306b\u305d\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u51fa\u529b\u3057\u3066\u3044\u308b\u3060\u3051\u3067\u3059\u3002<\/p>\n<p>\u3067\u3059\u306e\u3067\u3001\u753b\u9762\u4e0a\u306b<span>print<\/span>\u3059\u308b\u6642\u3084\u6587\u5b57\u5217\u3092\u89e3\u6790\u3057\u3066<span>Date<\/span>\u3092\u4f5c\u308b\u6642\u306a\u3069\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u610f\u8b58\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<h4>\uff14-\uff16-\uff11\uff0eCalendar\u3067\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u8a2d\u5b9a\u3059\u308b<\/h4>\n<p>Calendar\u3092<span>getInstance<\/span>\u3059\u308b\u3068\u3001\u30b7\u30b9\u30c6\u30e0\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u6301\u3063\u305f<span>Calendar<\/span>\u304c\u4f5c\u3089\u308c\u307e\u3059\u3002\u524d\u8ff0\u306e\u3068\u304a\u308a\u3001\u79c1\u306e\u30d1\u30bd\u30b3\u30f3\u306f\u65e5\u672c\u6642\u9593\u306a\u306e\u3067\u3001<span>Calendar<\/span>\u3082\u73fe\u5730\u6642\u9593\u306f<span>UTC<\/span>\u304b\u3089<span>9<\/span>\u6642\u9593\u9032\u3093\u3067\u3044\u308b\u3068\u307f\u306a\u3057\u3066\u51e6\u7406\u3092\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Calendar c = Calendar.getInstance();\r\nSystem.out.println(c.getTimeZone().getRawOffset()); \/\/ \u2192 32400000\u3001+9\u6642\u9593\u306e\u30df\u30ea\u79d2\u8868\u73fe<\/pre>\n<p>\u79c1\u306e\u74b0\u5883\u3067<span>Date<\/span>\u3092<span>Calendar<\/span>\u306b\u6e21\u3057\u3066\u65e5\u6642\u3092\u53d6\u5f97\u3059\u308b\u3068\u3001<span>UTC+0<\/span>\u304b\u3089<span>9<\/span>\u6642\u9593\u9032\u3093\u3060\u65e5\u6642\u304c\u5f97\u3089\u308c\u307e\u3059\u3002\u7e70\u308a\u8fd4\u3057\u3067\u3059\u304c\u3001<span>Date<\/span>\u305d\u306e\u3082\u306e\u306f<span>GMT<\/span>\u306a\u306e\u3067\u3001<span>GMT<\/span>\u304b\u3089\u73fe\u5730\u6642\u9593\u3078\u306e\u89e3\u91c8\u30fb\u5909\u63db\u3092<span>Calendar<\/span>\u304c\u884c\u3063\u3066\u3044\u308b\u306e\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ GMT\u30671970\/1\/1 00:00:00\u306eDate\u3092\u4f5c\u3063\u3066\u3082\u3001\r\nDate d = new Date(0); \/\/ 1970\/1\/1 00:00:00.000(GMT)\r\nSystem.out.println(d.getTime()); \/\/ \u2192 0\r\n\r\n\/\/ Calendar\u304b\u3089\u306f\u3001Calendar\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306b\u6e96\u3058\u305f\u65e5\u6642\u304c\u5f97\u3089\u308c\u308b\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\nSystem.out.println(c.get(Calendar.HOUR_OF_DAY)); \/\/ \u2192 9\u6642\u30010\u6642\u3067\u306f\u306a\u3044<\/pre>\n<p>\u3067\u3059\u304b\u3089\u3001<span>Calendar<\/span>\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u5207\u308a\u66ff\u3048\u308c\u3070\u3001\u540c\u3058\u65e5\u6642\u3092\u8868\u3059<span>Date<\/span>\u3067\u3042\u3063\u3066\u3082\u3001\u5225\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3067\u306e\u65e5\u6642\u3092\u53d6\u5f97\u3067\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ GMT\u30671970\/1\/1 00:00:00\u306eDate\u3092\u4f5c\u3063\u3066\u3082\u3001\r\nDate d = new Date(0); \/\/ 1970\/1\/1 00:00:00.000(GMT)\r\nSystem.out.println(d.getTime()); \/\/ \u2192 0\r\n\r\n\/\/ Calendar\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u5207\u308a\u66ff\u3048\u308c\u3070\u3001\r\nCalendar c = Calendar.getInstance();\r\nc.setTime(d);\r\nc.setTimeZone(TimeZone.getTimeZone(\"GMT-9\")); \/\/ Calendar\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092GMT-9\u306b\u5909\u66f4\r\n\r\n\/\/ Calendar\u304b\u3089\u53d6\u5f97\u3067\u304d\u308b\u65e5\u6642\u306f\u3001\u5168\u3066\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306b\u6e96\u3058\u305f\u3082\u306e\u306b\u306a\u3063\u3066\u3044\u308b\r\nSystem.out.println(c.get(Calendar.HOUR_OF_DAY)); \/\/ \u2192 15\u6642\u3001\u3064\u307e\u308a0\u6642(24\u6642) - 9\u6642\u9593\r\nSystem.out.println(c.get(Calendar.DAY_OF_MONTH)); \/\/ \u2192 31\r\nSystem.out.println(c.get(Calendar.MONTH)); \/\/ \u2192 11(12\u6708\u306e\u3053\u3068)\r\n\r\n\/\/ \u3067\u3082\u3001Calendar\u304c\u6301\u3063\u3066\u3044\u308b\u65e5\u6642\u305d\u306e\u3082\u306e\u306fGMT\r\nDate d2 = c.getTime();\r\nSystem.out.println(d2.getTime()); \/\/ \u2192 0\u3001Date\u305d\u306e\u3082\u306e\u306fGMT\r\nSystem.out.println(c.getTimeInMillis()); \/\/ \u2192 0\u3001Calendar\u304c\u8a8d\u8b58\u3057\u3066\u3044\u308b\u7d4c\u904e\u6642\u9593\u3082GMT<\/pre>\n<h4>\uff14-\uff16-\uff12\uff0eSimpleDateFormat\u3067\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u8a2d\u5b9a\u3059\u308b<\/h4>\n<p>SimpleDateFormat\u3082<span>Calendar<\/span>\u3068\u540c\u3058\u3067\u3001\u305d\u308c\u81ea\u8eab\u304c\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u6301\u3063\u3066\u3044\u307e\u3059\u3002\u3053\u3061\u3089\u3082\u3001\u4f55\u3082\u3057\u306a\u3051\u308c\u3070\u30b7\u30b9\u30c6\u30e0\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3067\u3059\u3002\u3067\u3059\u306e\u3067\u3001\u51fa\u529b\u3084\u89e3\u6790\u306f\u30b7\u30b9\u30c6\u30e0\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306b\u6e96\u62e0\u3057\u305f\u3082\u306e\u306b\u306a\u308b\u306e\u3067\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ GMT\u30671970\/1\/1 00:00:00\u306eDate\u3092\u4f5c\u3063\u3066\u3082\u3001\r\nDate d = new Date(0); \/\/ 1970\/1\/1 00:00:00.000(GMT)\r\nSystem.out.println(d.getTime()); \/\/ \u2192 0\r\n\r\n\/\/ SimpleDateFormat\u306e\u51fa\u529b\u306f\u30b7\u30b9\u30c6\u30e0\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u8003\u616e\u3057\u305f\u7d50\u679c\u306b\u306a\u308b\r\nSimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\nSystem.out.println(df.format(d)); \/\/ \u2192 1970\/01\/01 09:00:00.000\u30019\u6642\u9593\u9032\u3093\u3067\u3044\u308b<\/pre>\n<p>SimpleDateFormat\u304c\u6301\u3064\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u5909\u3048\u308b\u306b\u306f\u3001<span>Calendar<\/span>\u3068\u540c\u3058\u3088\u3046\u306b\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u6307\u5b9a\u3057\u307e\u3059\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">Date d = new Date(0); \/\/ 1970\/1\/1 00:00:00.000(GMT)\r\nSystem.out.println(d.getTime()); \/\/ \u2192 0\r\n\r\n\/\/ SimpleDateFormat\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u5909\u66f4\u3059\u308c\u3070\u3001\u305d\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306e\u51fa\u529b\u306b\u306a\u308b\r\nSimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss.SSS\");\r\ndf.setTimeZone(TimeZone.getTimeZone(\"GMT-9\")); \/\/ SimpleDateFormat\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092GMT-9\u306b\u5909\u66f4\r\nSystem.out.println(df.format(d)); \/\/ \u2192 1970\/01\/01 00:00:00.000<\/pre>\n<h4>\uff14-\uff16-\uff13\uff0e\u65e5\u6642\u6587\u5b57\u5217\u3092\u89e3\u6790\u3059\u308b\u6642\u306f\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u610f\u8b58\u3057\u3088\u3046<\/h4>\n<p>\u3053\u306e\u7bc0\u3067\u898b\u3066\u304d\u305f\u3088\u3046\u306b\u3001<span>Java<\/span>\u3067\u306e\u65e5\u6642\u306e\u6839\u672c\u7684\u306a\u8868\u73fe\u65b9\u6cd5\u306f<span>GMT<\/span>\u3067\u3059\u3002\u305d\u306e\u65e5\u6642\u304c\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5916\u304b\u3089\u3069\u3046\u898b\u3048\u308b\u304b\u306f\u3001\u30b7\u30b9\u30c6\u30e0\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3084\u3001<span>Calendar<\/span>\u3084<span>DateFormatter<\/span>\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u306b\u4f9d\u5b58\u3057\u307e\u3059\u3002<\/p>\n<p>\u305f\u3060\u3001\u30d7\u30ed\u30b0\u30e9\u30e0\u5916\u90e8\u304b\u3089\u53d6\u308a\u8fbc\u3093\u3060\u60c5\u5831\u3001\u7279\u306b\u6587\u5b57\u5217\u3068\u3057\u3066\u53d6\u308a\u8fbc\u3093\u3060\u65e5\u6642\u304c\u3001\u3069\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3067\u8868\u73fe\u3055\u308c\u3066\u3044\u308b\u3082\u306e\u304b\u306f\u610f\u8b58\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u305d\u3046\u3057\u306a\u3044\u3068\u3001<span>Date<\/span>\u3078\u5909\u63db\u3057\u305f\u6642\u306b\u6642\u523b\u304c\u305a\u308c\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u7279\u306b\u6587\u5b57\u5217\u3092\u65e5\u6642\u3068\u3057\u3066\u89e3\u91c8\u3059\u308b\u6642\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u8868\u3059\u3082\u306e\u304c\u4ed8\u3044\u3066\u3044\u308c\u3070\u3001\u305d\u308c\u306b\u6e96\u3058\u3066\u89e3\u91c8\u3059\u308c\u3070\u3044\u3044\u3060\u3051\u3067\u3059\u3002\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u304c\u3064\u3044\u3066\u3044\u306a\u3044\u306a\u3089\u3001\u3069\u306e\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u304b\u3092\u304d\u3061\u3093\u3068\u78ba\u8a8d\u3057\u3066\u6307\u5b9a\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ \u3053\u306e\u6587\u5b57\u5217\u306f\u5b9f\u306fGMT\u306a\u306e\u3060\u3051\u308c\u3069\u3082\u3001\r\nString dateStr = \"1970\/01\/01 00:00:00\";\r\n\/\/ \u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u610f\u8b58\u3057\u306a\u3044\u3067\u3001\u30b7\u30b9\u30c6\u30e0\u306e\u30c7\u30d5\u30a9\u30eb\u30c8(UTC+9)\u3067\u89e3\u6790\u3059\u308b\u3068\u3001\r\nSimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss\");\r\nDate d = df.parse(dateStr);\r\n\/\/ Date\u306eGMT\u3067\u306f9\u6642\u9593\u524d\u306e\u65e5\u6642\u306b\u306a\u308a\u3001\u6587\u5b57\u5217\u306e\u65e5\u6642\u304b\u3089\u305a\u308c\u3066\u3057\u307e\u3046\r\nSystem.out.println(d.getTime()); \/\/ \u2192 -32400000\u30019\u6642\u9593\u524d<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ \u6587\u5b57\u5217\u306b\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u304c\u4ed8\u3044\u3066\u3044\u3066\u3001\r\nString dateStr = \"1970\/01\/01 00:00:00+00:00\";\r\n\/\/ \u89e3\u6790\u3059\u308b\u66f8\u5f0f\u3078\u3082\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u6307\u5b9a\u3067\u304d\u3066\u3044\u308c\u3070\u3001\r\nSimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ssXXX\");\r\nDate d = df.parse(dateStr);\r\n\/\/ Date\u3067\u306e\u65e5\u6642\u3082\u305a\u308c\u306a\u3044\r\nSystem.out.println(d.getTime()); \/\/ \u2192 0\u30010\u66420\u52060\u79d2\u306a\u306e\u3067\u3001\u6587\u5b57\u5217\u3068\u5408\u3063\u3066\u3044\u308b<\/pre>\n<pre class=\"prettyprint lang:default decode:true\">\/\/ \u3042\u308b\u3044\u306f\u3001GMT\u306e\u65e5\u6642\u6587\u5b57\u5217\u306b\u5bfe\u3057\u3066\u3001\r\nString dateStr = \"1970\/01\/01 00:00:00\";\r\n\/\/ \u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u30d7\u30ed\u30b0\u30e9\u30e0\u4e0a\u3067\u660e\u793a\u7684\u306b\u6307\u5b9a\u3067\u304d\u3066\u3044\u308c\u3070\u3001\r\nSimpleDateFormat df = new SimpleDateFormat(\"yyyy\/MM\/dd HH:mm:ss\");\r\ndf.setTimeZone(TimeZone.getTimeZone(\"GMT\"));\r\nDate d = df.parse(dateStr);\r\n\/\/ Date\u3067\u306e\u65e5\u6642\u3082\u305a\u308c\u306a\u3044\r\nSystem.out.println(d.getTime()); \/\/ \u2192 0\u30010\u66420\u52060\u79d2\u306a\u306e\u3067\u3001\u6587\u5b57\u5217\u3068\u5408\u3063\u3066\u3044\u308b<\/pre>\n<h2><span id=\"Date_and_Time_API\">\uff15\uff0e\u3010\u53c2\u8003\u3011Date and Time API\u306e\u7c21\u5358\u306a\u7d39\u4ecb<\/span><\/h2>\n<p>Java 8\u3088\u308a\u3001Date and Time API\u3068\u3044\u3046\u3001\u65e5\u6642\u3092\u53d6\u308a\u6271\u3046\u65b0\u3057\u3044API\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002\u30d1\u30c3\u30b1\u30fc\u30b8\u3068\u3057\u3066<span>java.time<\/span>\u304c\u65b0\u8a2d\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<blockquote>\n<p>java.time (Java SE 12 &amp; JDK 12)<\/p>\n<p><a href=\"https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/time\/package-summary.html\">https:\/\/docs.oracle.com\/javase\/jp\/12\/docs\/api\/java.base\/java\/time\/package-summary.html<\/a><\/p>\n<\/blockquote>\n<p>\u3053\u308c\u306b\u3088\u308a\u3001\u4eca\u307e\u3067\u306e<span>java.util.Date<\/span>\u3084<span>java.util.Calendar<\/span>\u3001<span>java.text.DateFormat<\/span>\u306f\u53e4\u3044<span>API<\/span>\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3082\u3061\u308d\u3093\u3053\u308c\u304b\u3089\u3082\u4f7f\u3048\u307e\u3059\u304c\u3001\u6a5f\u80fd\u8ffd\u52a0\u30fb\u5f37\u5316\u306f\u3001\u65b0<span>API<\/span>\u306e\u65b9\u304c\u512a\u5148\u3055\u308c\u3066\u3044\u304f\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u3053\u3053\u3067\u306f\u3001\u3053\u306e\u65b0\u3057\u3044<span>API<\/span>\u306b\u63a5\u3059\u308b\u306b\u5f53\u305f\u308a\u3001\u4eca\u307e\u3067\u306e<span>Date<\/span>\u3068\u3069\u3046\u3044\u3046\u9055\u3044\u304c\u3042\u308b\u306e\u304b\u3092\u7c21\u5358\u306b\u304a\u4f1d\u3048\u3057\u307e\u3059\u3002<\/p>\n<h3><span id=\"-DateCalendar\">\uff15-\uff11\uff0eDate\/Calendar\u3057\u304b\u306a\u3044\u3053\u3068\u306e\u554f\u984c\u70b9<\/span><\/h3>\n<p>\u4eca\u307e\u3067\u306e<span>API<\/span>\u306f<span>Date<\/span>\u3084<span>Calendar<\/span>\u304c\u305d\u306e\u4e2d\u5fc3\u306b\u3042\u308a\u307e\u3057\u305f\u3002\u3067\u3059\u306e\u3067\u3001<span>Date\/Calendar<\/span>\u3067\u4fdd\u6301\u3057\u3066\u3044\u308b\u65e5\u6642\u3092\u3069\u3046\u6271\u3046\u304b\u3001\u3068\u3044\u3046<span>API<\/span>\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u3067\u3059\u304c\u3001\u3044\u304f\u3064\u304b\u306e\u554f\u984c\u304c\u6614\u304b\u3089\u6307\u6458\u3055\u308c\u3066\u3044\u307e\u3057\u305f\u3002<\/p>\n<p>\u305d\u306e\u4e00\u3064\u306b\u3001<span>Date<\/span>\u306f\u6301\u3063\u3066\u3044\u308b\u65e5\u6642\u306e\u5358\u4f4d\u304c\u5e38\u306b\u30df\u30ea\u79d2\u306a\u306e\u3067\u3001\u7528\u9014\u306b\u3088\u3063\u3066\u306f\u30e1\u30bd\u30c3\u30c9\u3084\u30e1\u30bd\u30c3\u30c9\u306e\u623b\u308a\u5024\u306e\u610f\u5473\u304c\u3042\u3044\u307e\u3044\u306b\u306a\u3063\u3066\u3057\u307e\u3046\u3001\u3068\u3044\u3046\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002\u3053\u308c\u306f<span>Calendar<\/span>\u3067\u3082\u540c\u3058\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001\u30e1\u30bd\u30c3\u30c9\u306e\u5f15\u6570\u304c<span>Date<\/span>\u3060\u3068\u3057\u3066\u3001\u305d\u306e<span>Date<\/span>\u306f\u5e74\u6708\u65e5\u3060\u3051\u5fc5\u8981\u306a\u306e\u304b\u3001\u305d\u308c\u3068\u3082\u30df\u30ea\u79d2\u307e\u3067\u5fc5\u8981\u306a\u306e\u304b\u306f\u308f\u304b\u308a\u307e\u305b\u3093\u3002<span>Javadoc<\/span>\u304c\u3042\u308c\u3070\u307e\u3060\u30de\u30b7\u3067\u3059\u304c\u3001\u306a\u3051\u308c\u3070\u304a\u624b\u4e0a\u3052\u306a\u306e\u3067\u3001\u30bd\u30fc\u30b9\u3092\u8aad\u3080\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>Date\u3067\u306f\u554f\u984c\u306a\u306e\u3067<span>String<\/span>\u3084<span>int<\/span>\u3092\u4f7f\u3063\u305f\u3068\u3057\u3066\u3082\u3001\u30e1\u30bd\u30c3\u30c9\u5ba3\u8a00\u4e0a\u306f\u3069\u3093\u306a<span>String\/int<\/span>\u3067\u3082\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306f\u306a\u3089\u306a\u3044\u306e\u3067\u3001<span>&#8220;YYYY\/MM\/DD&#8221;<\/span>\u3092\u60f3\u5b9a\u3057\u305f\u30e1\u30bd\u30c3\u30c9\u3060\u3068\u3057\u3066\u3082\u3001\u30e1\u30bd\u30c3\u30c9\u5185\u3067\u306e\u30c1\u30a7\u30c3\u30af\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n<h3><span id=\"i-7\">\uff15-\uff12\uff0e\u65e5\u6642\u306e\u7a2e\u985e\u304c\u30af\u30e9\u30b9\u306b\u306a\u3063\u3066\u660e\u78ba\u306b<span>!!<\/span><\/span><\/h3>\n<p>\u7d50\u5c40\u3001\u554f\u984c\u306f\u65e5\u6642\u306e\u5f79\u5272\u3092<span>Date<\/span>\u3068<span>Calendar<\/span>\u3060\u3051\u3067\u30ab\u30d0\u30fc\u3057\u3088\u3046\u3068\u3057\u305f\u3053\u3068\u3067\u3059\u3002\u3067\u3059\u306e\u3067\u3001<span>Date and Time API<\/span>\u3067\u306f\u3001\u7528\u9014\u5225\u306e\u30af\u30e9\u30b9\u3067\u5f79\u5272\u5206\u62c5\u3092\u3059\u308b\u3053\u3068\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u305d\u308c\u304c\u5f93\u6765\u306e\u3082\u306e\u304b\u3089\u5927\u304d\u304f\u5909\u308f\u3063\u305f\u3068\u3053\u308d\u3067\u3059\u3002<\/p>\n<p>\u307e\u305f\u3001\u30af\u30e9\u30b9\u304c\u591a\u304f\u306a\u3063\u305f\u306e\u3067\u3059\u304c\u3001\u305d\u308c\u305e\u308c\u306e\u30af\u30e9\u30b9\u306e\u64cd\u4f5c\u3092\u3059\u308b\u30e1\u30bd\u30c3\u30c9\u540d\u306b\u306f\u7d71\u4e00\u3055\u308c\u305f\u30eb\u30fc\u30eb\u304c\u3042\u308a\u3001\u610f\u5473\u304c\u5206\u304b\u308a\u3084\u3059\u304f\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u306f\u3001\u540c\u3058\u304f<span>Java 7<\/span>\u306b<span>NIO.2<\/span>\u3067\u8ffd\u52a0\u3055\u308c\u305f\u30af\u30e9\u30b9\u306b\u3082\u5171\u901a\u3057\u305f\u7279\u5fb4\u3067\u3059\u3002<\/p>\n<p>\u306a\u304a\u3001\u3053\u3053\u3067\u7d39\u4ecb\u3059\u308b\u30af\u30e9\u30b9\u306f\u5168\u3066\u4e0d\u5909<span>(Immutable)<\/span>\u3001\u304b\u3064\u30b9\u30ec\u30c3\u30c9\u30bb\u30fc\u30d5\u3067\u3059\u3002<\/p>\n<h4>\uff15-\uff12-\uff11\uff0e\u65e5\u6642\u306e\u30af\u30e9\u30b9<\/h4>\n<p>\u65e5\u6642\u3092\u76f4\u63a5\u8868\u3059\u30af\u30e9\u30b9\u3068\u3057\u3066\u306f\u3001\u4ee5\u4e0b\u306e\u3082\u306e\u304c\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<ul>\n<li><span>java.time.Instant<\/span>\uff1a\u30bf\u30a4\u30e0\u30b9\u30bf\u30f3\u30d7\u306e\u3088\u3046\u306a\u3082\u306e\u3002\u610f\u5473\u7684\u306b\u306f\u3053\u308c\u304c\u5f93\u6765\u306e<span>Date<\/span>\u306b\u4e00\u756a\u8fd1\u3044<span>?<\/span><\/li>\n<li><span>java.time.LocalTime<\/span>\uff1a\u6642\u523b\u3060\u3051\u3092\u6301\u3064\u30af\u30e9\u30b9\u3002\u5e74\u6708\u65e5\u306e\u60c5\u5831\u306f\u6301\u305f\u306a\u3044\u3002<\/li>\n<li><span>java.time.LocalDate<\/span>\uff1a\u65e5\u4ed8<span>(<\/span>\u5e74\u6708\u65e5<span>)<\/span>\u3060\u3051\u3092\u6301\u3064\u30af\u30e9\u30b9\u3002\u6642\u5206\u79d2\u4ee5\u4e0b\u306e\u60c5\u5831\u306f\u3082\u305f\u306a\u3044\u3002<\/li>\n<li><span>java.time.LocalDateTime<\/span>\uff1a\u65e5\u6642\u3092\u6301\u3064\u30af\u30e9\u30b9\u3002\u305f\u3060\u3057\u3001\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3084\u6642\u5dee\u306e\u60c5\u5831\u306f\u6301\u305f\u306a\u3044\u3002<\/li>\n<li><span>java.time.ZonedDateTime<\/span>\uff1a\u65e5\u6642\u3068\u7d10\u4ed8\u304f\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3092\u540c\u6642\u306b\u6301\u3064\u30af\u30e9\u30b9\u3002<\/li>\n<li><span>java.time.OffsetDateTime<\/span>\uff1a\u65e5\u6642\u3068\u7d10\u4ed8\u304f\u6642\u5dee\u3092\u540c\u6642\u306b\u6301\u3064\u30af\u30e9\u30b9\u3002<\/li>\n<\/ul>\n<p>\u3053\u3053\u3067<span>ZonedDateTime<\/span>\u3068<span>OffsetDateTime<\/span>\u306f\u540c\u3058\u3082\u306e\u306b\u898b\u3048\u307e\u3059\u304c\u5225\u7269\u3067\u3059\u3002\u30bf\u30a4\u30e0\u30be\u30fc\u30f3\u3068\u6642\u5dee\u306f\u3001\u5b9f\u306f\u5c11\u3005\u9055\u3046\u8003\u3048\u65b9\u3060\u304b\u3089\u3067\u3059\u3002\u3053\u3053\u3067\u306f\u8a73\u7d30\u306b\u306f\u8e0f\u307f\u8fbc\u307f\u307e\u305b\u3093\u306e\u3067\u3001\u8208\u5473\u304c\u3042\u308b\u65b9\u306f\u8abf\u3079\u3066\u307f\u3066\u3082\u3044\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<h4>\uff15-\uff12-\uff12\uff0e\u671f\u9593\u306e\u30af\u30e9\u30b9<\/h4>\n<p>\u65b0\u3057\u3044\u7a2e\u985e\u306e\u30c7\u30fc\u30bf\u578b\u3068\u3057\u3066\u3001\u671f\u9593\u3092\u8868\u73fe\u3067\u304d\u308b\u30af\u30e9\u30b9\u304c\u4e8c\u3064\u3067\u304d\u307e\u3057\u305f\u3002<\/p>\n<ul>\n<li><span>java.time.Duration<\/span>\uff1a\u671f\u9593\u3092\u30ca\u30ce\u79d2\u5358\u4f4d\u3067\u8868\u73fe\u3067\u304d\u308b\u30af\u30e9\u30b9\u3002<\/li>\n<li><span>java.time.Period<\/span>\uff1a\u671f\u9593\u3092\u3001\u4f55\u5e74\u30fb\u4f55\u30f6\u6708\u30fb\u4f55\u65e5\u306a\u3069\u3001\u4eba\u9593\u304c\u5206\u304b\u308a\u3084\u3059\u3044\u5f62\u3067\u8868\u73fe\u3057\u305f\u30af\u30e9\u30b9\u3002<\/li>\n<\/ul>\n<h4>\uff15-\uff12-\uff13\uff0e\u5e74\u6708\u65e5\u30fb\u66dc\u65e5\u30fb\u6642\u5dee\u306e\u30af\u30e9\u30b9<\/h4>\n<p>\u5e74\u30fb\u6708\u30fb\u65e5\u30fb\u66dc\u65e5\u30fb\u6642\u5dee\u306a\u3069\u3082\u3001\u305d\u308c\u305e\u308c\u30af\u30e9\u30b9\u3068\u3057\u3066\u6271\u3048\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3053\u308c\u3067\u30e1\u30bd\u30c3\u30c9\u306e\u5f15\u6570\u3084\u623b\u308a\u5024\u306e\u610f\u5473\u3092\u3001\u3088\u308a\u660e\u78ba\u306b\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n<ul>\n<li>java.time.Year\uff1a\u5e74<\/li>\n<li>java.time.Month\uff1a\u6708<\/li>\n<li>java.time.YearMonth\uff1a\u5e74\u6708<\/li>\n<li>java.time.MonthDay\uff1a\u6708\u65e5<\/li>\n<li><span>java.time.DayOfWeek<\/span>\uff1a\u66dc\u65e5<\/li>\n<li><span>java.time.OffsetTime<\/span>\uff1a\u6642\u5dee\u306e\u30aa\u30d5\u30bb\u30c3\u30c8\u6642\u9593<span>(+01:00<\/span>\u306a\u3069<span>)<\/span><\/li>\n<\/ul>\n<h3><span id=\"i-8\">\uff15-\uff13\uff0e\u65e5\u6642\u7528\u306e\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u30fb\u89e3\u6790\u7528\u30af\u30e9\u30b9\u304c\u65b0\u3057\u304f\u3067\u304d\u305f<\/span><\/h3>\n<p>\u4eca\u307e\u3067\u306eDateFormat(SimpleDateFormat)\u306b\u4ee3\u308f\u308a\u3001java.time\u306b\u3042\u308b\u30af\u30e9\u30b9\u7528\u306e\u30d5\u30a9\u30fc\u30de\u30c3\u30c8\u30fb\u89e3\u6790\u7528\u30af\u30e9\u30b9java.time.format.DateTimeFormatter\u304c\u65b0\u3057\u304f\u51fa\u6765\u307e\u3057\u305f\u3002\u5f93\u6765\u306e\u3082\u306e\u3088\u308a\u6a5f\u80fd\u304c\u5f37\u5316\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u305d\u3057\u3066\u3001\u4f8b\u3048\u3070<span>ISO 8601<\/span>\u306a\u3069\u306e\u5404\u7a2e\u6a19\u6e96\u306b\u5247\u3063\u305f\u66f8\u5f0f\u7528\u306e\u30d5\u30a9\u30fc\u30de\u30c3\u30bf\u304c\u3001\u3042\u3089\u304b\u3058\u3081\u3044\u304f\u3064\u304b\u7528\u610f\u3055\u308c\u3066\u3044\u307e\u3059\u3002\u3067\u3059\u304b\u3089\u3001<span>SimpleDateFormat<\/span>\u306e\u3088\u3046\u306b\u3001\u81ea\u5206\u3067\u66f8\u5f0f\u6587\u5b57\u5217\u3092\u8003\u3048\u306a\u304f\u3066\u3082\u3059\u3080\u3053\u3068\u304c\u591a\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u307e\u305f\u3001<span>DateTimeFormatter<\/span>\u306f\u30b9\u30ec\u30c3\u30c9\u30bb\u30fc\u30d5\u3067\u3059\u3002\u305d\u306e\u305f\u3081\u3001\u4eca\u307e\u3067\u306e<span>SimpleDateFormat<\/span>\u306e\u3088\u3046\u306b\u3001\u4e0d\u5177\u5408\u56de\u907f\u306e\u305f\u3081\u306b\u7121\u99c4\u306b<span>new<\/span>\u3059\u308b\u5fc5\u8981\u3082\u3042\u308a\u307e\u305b\u3093\u3002\u6700\u521d\u306b\u4e00\u3064\u4f5c\u3063\u3066\u304a\u304f\u304b\u3001\u3082\u3046\u3042\u308b\u3082\u306e\u3092\u4f7f\u3048\u3070\u3044\u3044\u306e\u3067\u3059\u3002<\/p>\n<h3><span id=\"i-9\">\uff15-\uff14\uff0e\u65e5\u6642\u306e\u7cbe\u5ea6\u304c\u30ca\u30ce\u79d2\u5358\u4f4d\u306b\u306a\u3063\u305f<\/span><\/h3>\n<p>\u5730\u5473\u306b\u6a5f\u80fd\u5f37\u5316\u3055\u308c\u305f\u30dd\u30a4\u30f3\u30c8\u306f\u3001\u5404\u7a2e\u65e5\u6642\u306e\u7cbe\u5ea6\u306e\u4ed5\u69d8\u304c\u3001\u4eca\u307e\u3067\u306e\u30df\u30ea\u79d2<span>(1\/1000<\/span>\u79d2<span>)<\/span>\u304b\u3089\u30ca\u30ce\u79d2<span>(1\/1000000000<\/span>\u79d2<span>)<\/span>\u306b\u306a\u3063\u305f\u3053\u3068\u3067\u3059\u3002<\/p>\n<p>\u5b9f\u969b\u306e\u3068\u3053\u308d\u3001\u30ca\u30ce\u79d2\u307e\u3067\u306e\u7cbe\u5ea6\u304c\u3042\u3063\u305f\u3068\u3057\u3066\u3082\u3001\u666e\u901a\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u3067\u306f\u307e\u305a\u4f7f\u3044\u307e\u305b\u3093\u3002\u3067\u3059\u304c\u3001\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u8a00\u8a9e\u306e\u4ed5\u69d8\u4e0a\u3067\u304d\u308b\u3068\u3044\u3046\u3053\u3068\u3068\u3001\u3067\u304d\u306a\u3044\u3068\u3044\u3046\u3053\u3068\u306e\u9593\u306b\u306f\u3001\u5929\u3068\u5730\u307b\u3069\u306e\u5dee\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>\u305d\u308c\u306b\u3001\u305d\u3046\u3044\u3046\u6642\u9593\u306e\u7cbe\u5ea6\u304c\u5fc5\u8981\u3068\u306a\u308b\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u9818\u57df\u3082\u3042\u308b\u306e\u3067\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001<span>Java<\/span>\u3092\u9069\u7528\u3067\u304d\u308b\u9818\u57df\u304c\u3001\u307e\u305f\u5927\u304d\u304f\u5e83\u304c\u308b\u3053\u3068\u306b\u306a\u308b\u3067\u3057\u3087\u3046\u3002<\/p>\n<h2><span id=\"i-10\">\uff16\uff0e\u307e\u3068\u3081<\/span><\/h2>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001<span>Java<\/span>\u3067\u65e5\u6642\u3092\u6271\u3046\u305f\u3081\u306e\u30af\u30e9\u30b9<span>java.util.Date<\/span>\u3092\u3054\u7d39\u4ecb\u3057\u307e\u3057\u305f\u3002<span>Date<\/span>\u306f\u57fa\u6e96\u65e5\u6642\u304b\u3089\u306e\u7d4c\u904e\u6642\u9593\u306e\u30df\u30ea\u79d2\u3092\u6301\u3064\u3060\u3051\u306e\u5358\u7d14\u306a\u30af\u30e9\u30b9\u3067\u3059\u304c\u3001\u3053\u306e\u30af\u30e9\u30b9\u304c<span>Java<\/span>\u306e\u65e5\u6642\u51e6\u7406\u3092\u9577\u3089\u304f\u652f\u3048\u3066\u304d\u307e\u3057\u305f\u3002<\/p>\n<p>\u305d\u3057\u3066\u3001<span>Date<\/span>\u3060\u3051\u3067\u306f\u5c11\u3005\u4f7f\u3044\u3065\u3089\u3044\u305f\u3081\u3001<span>Date<\/span>\u306b\u6b20\u3051\u3066\u3044\u308b\u6a5f\u80fd\u3092\u88dc\u5b8c\u3059\u308b\u305f\u3081\u306e<span>Calendar<\/span>\u3084<span>DateFormat(SimpleDateFormat)<\/span>\u304c\u3042\u308a\u307e\u3059\u3002<span>Java<\/span>\u306e\u65e5\u6642\u51e6\u7406\u306f\u3001\u3053\u308c\u3089\u306e\u30af\u30e9\u30b9\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u884c\u3046\u306e\u3067\u3059\u3002<\/p>\n<p>Java 12\u306e\u4eca\u3067\u306f\u3001\u516c\u5f0f\u306b\u306f<span>Date<\/span>\u306e\u5f79\u5272\u306f\u7d42\u308f\u308a\u307e\u3057\u305f\u3002<span>Java 8<\/span>\u304b\u3089\u306f<span>java.time<\/span>\u306b\u3042\u308b<span>Date and Time API<\/span>\u304c\u516c\u5f0f\u306e<span>API<\/span>\u306b\u306a\u308a\u307e\u3057\u305f\u306e\u3067\u3001\u3053\u308c\u304b\u3089\u306f\u305d\u308c\u3089\u3092\u4f7f\u3063\u305f<span>API<\/span>\u3084\u30d7\u30ed\u30b0\u30e9\u30e0\u304c\u5897\u3048\u3066\u3044\u304f\u3067\u3057\u3087\u3046\u3002<\/p>\n<p>\u3057\u304b\u3057\u3001<span>Date<\/span>\u304c\u306a\u304f\u306a\u308b\u3053\u3068\u306f\u306a\u3044\u3067\u3057\u3087\u3046\u3057\u3001\u5404\u7a2e\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3084<span>API<\/span>\u3082<span>Date<\/span>\u3057\u304b\u6271\u3048\u306a\u3044\u3082\u306e\u304c\u307e\u3060\u3042\u308a\u307e\u3059\u3002\u3067\u3059\u304b\u3089\u3001<span>Date<\/span>\u306e\u4f7f\u3044\u65b9\u3092\u8eab\u306b\u7740\u3051\u308b\u3053\u3068\u306f\u3001\u4eca\u306e<span>Java<\/span>\u30d7\u30ed\u30b0\u30e9\u30de\u306b\u306f\u307e\u3060\u5fc5\u8981\u306a\u3053\u3068\u306a\u306e\u3067\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Java\u306ejava.util.Date\u306f\u3001\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3092\u8868\u73fe\u3057\u3066\u3044\u308b\u30af\u30e9\u30b9\u3067\u3059\u3002\u3053\u3053\u3067\u8a00\u3046\u7279\u5b9a\u30bf\u30a4\u30df\u30f3\u30b0\u306e\u65e5\u6642\u3068\u306f\u3001\u4f55\u5e74\u4f55\u6708\u4f55\u65e5\u30fb\u4f55\u6642\u4f55\u5206\u4f55\u79d2\u30fb\u4f55\u30df\u30ea\u79d2\u3068\u3044\u3046\u7279\u5b9a\u306e\u4e00\u77ac\u3001\u305d\u306e\u65e5\u6642\u306e\u3053\u3068\u3067\u3059\u3002 \u30b3\u30f3\u30d4\u30e5\u30fc\u30bf\u306f\u5168\u3066\u3092 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