Java:如何在 UTC 中获取“1000-01-01 00:00:00"的时间戳? [英] Java: How to get the timestamp of '1000-01-01 00:00:00' in UTC?

问题描述

我在两个不同的结果中得到了1000-01-01 00:00:00"的时间戳.有人知道为什么吗?

I got the timestamp of '1000-01-01 00:00:00' in two different results. Does anybody know why?

TimeZone timeZone = TimeZone.getTimeZone(ZoneOffset.UTC);
GregorianCalendar calendar = new GregorianCalendar(timeZone);
calendar.clear();
calendar.set(1000, 0, 1, 0, 0, 0);
System.out.println(calendar.getTimeInMillis()); // print -30609792000000
System.out.println(ZonedDateTime.of(1000, 1, 1,0, 0, 0, 0, timeZone.toZoneId()).toInstant().toEpochMilli()); // print -30610224000000

推荐答案

GregorianCalendar 尽管它的名字使用的是儒略历，但在公历从 1582 年开始引入之前.相比之下，ZonedDateTime 使用 Proleptic 公历a>，也就是说，将公历外推到当时没有使用它的世纪.

GregorianCalendar despite its name uses the Julian calendar for the time before the Gregorian calendar was introduced from 1582 and onward. ZonedDateTime by contrast uses the Proleptic Gregorian calendar, that is, extrapolates the Gregorian calendar into the centuries where it wasn’t used at that time.

所以您实际上是在使用两个日历系统.这就解释了为什么你会得到两个不同的结果.

So you are really using two calendar systems. Which explains why you are getting two different results.

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