从纪元后的几天开始获取java.util.Calendar

Calendar c = new GregorianCalendar();
c.setTime(new Date(0));

c.add(Calendar.DAY_OF_YEAR, 1000);

System.err.println(c.getTime());

TimeZone.setDefault(TimeZone.getTimeZone(\"GMT-1\"));

Calendar c = new GregorianCalendar();
c.setTimeInMillis(0);

System.err.println(c.getTime());
System.err.println(c.get(Calendar.DAY_OF_YEAR));

c.add(Calendar.DAY_OF_YEAR, 1);
System.err.println(c.getTime());
System.err.println(c.get(Calendar.DAY_OF_YEAR));

Wed Dec 31 23:00:00 GMT-01:00 1969
365
Thu Jan 01 23:00:00 GMT-01:00 1970
1

c.get(Calendar.DAY_OF_YEAR)

new GregorianCalendar(TimeZone.getTimeZone(\"GMT\"))

Wed Dec 31 23:00:00 GMT-01:00 1969
1
Thu Jan 01 23:00:00 GMT-01:00 1970
2

c.getTime()

Date

toString()

TimeZone

LocalDate date = LocalDate.ofEpochDay(1000);

ofEpochDay(long epochDay)

LocalDate

Calendar cal = new GregorianCalendar();
cal.setTimeInMillis(0);
cal.add(Calendar.DAY_OF_MONTH, daysSinceEpoch);