时区 : America/Mexico_City 中文:美国中部时间(墨西哥城) 的夏令时

方法: (参数为:

TimeZone timeZone = TimeZone.getTimeZone("America/Mexico_City");

private static void testDayTime(TimeZone timeZone) {
        System.out.println("Time Zone is : " + timeZone.getDisplayName() + " : " + timeZone.getID());

        DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        Calendar start = Calendar.getInstance(timeZone);
        start.setTime(new Date(0)); // UTC 1970-01-01
        System.out.println("start=" + df.format(start.getTime()));  // will print: start=1970-01-01 08:00:00

        Calendar end = Calendar.getInstance(timeZone);
        end.add(Calendar.YEAR, 5);
        System.out.println("end=" + df.format(end.getTime()));

        boolean find = false;
        for (long i = start.getTimeInMillis(); i < end.getTimeInMillis(); i = start.getTimeInMillis()) {
            start.add(Calendar.DATE, 1); // add one day

            if ((start.getTimeInMillis() - i) % (24 * 3600 * 1000L) != 0) { // 是否能被24整除
                find = true;

                System.out.println("from " + df.format(new Date(i)) + " to " + df.format(start.getTime()) + " has "
                        + (start.getTimeInMillis() - i) + "ms" + "[" + (start.getTimeInMillis() - i) / (3600 * 1000L)
                        + "hours]");
            }

        }

        if (!find) {
            System.out.println("Every day is ok.");
        }
    }

I: Time Zone is : Central Standard Time : America/Mexico_City
I: start=1969-12-31 18:00:00
I: end=2021-01-07 21:24:34
I: from 1996-04-06 18:00:00 to 1996-04-07 18:00:00 has 82800000ms[23hours]
I: from 1996-10-26 18:00:00 to 1996-10-27 18:00:00 has 90000000ms[25hours]
I: from 1997-04-05 18:00:00 to 1997-04-06 18:00:00 has 82800000ms[23hours]
I: from 1997-10-25 18:00:00 to 1997-10-26 18:00:00 has 90000000ms[25hours]
I: from 1998-04-04 18:00:00 to 1998-04-05 18:00:00 has 82800000ms[23hours]
I: from 1998-10-24 18:00:00 to 1998-10-25 18:00:00 has 90000000ms[25hours]
I: from 1999-04-03 18:00:00 to 1999-04-04 18:00:00 has 82800000ms[23hours]
I: from 1999-10-30 18:00:00 to 1999-10-31 18:00:00 has 90000000ms[25hours]
I: from 2000-04-01 18:00:00 to 2000-04-02 18:00:00 has 82800000ms[23hours]
I: from 2000-10-28 18:00:00 to 2000-10-29 18:00:00 has 90000000ms[25hours]
I: from 2001-05-05 18:00:00 to 2001-05-06 18:00:00 has 82800000ms[23hours]
I: from 2001-09-29 18:00:00 to 2001-09-30 18:00:00 has 90000000ms[25hours]
I: from 2002-04-06 18:00:00 to 2002-04-07 18:00:00 has 82800000ms[23hours]
I: from 2002-10-26 18:00:00 to 2002-10-27 18:00:00 has 90000000ms[25hours]
I: from 2003-04-05 18:00:00 to 2003-04-06 18:00:00 has 82800000ms[23hours]
I: from 2003-10-25 18:00:00 to 2003-10-26 18:00:00 has 90000000ms[25hours]
I: from 2004-04-03 18:00:00 to 2004-04-04 18:00:00 has 82800000ms[23hours]
I: from 2004-10-30 18:00:00 to 2004-10-31 18:00:00 has 90000000ms[25hours]
I: from 2005-04-02 18:00:00 to 2005-04-03 18:00:00 has 82800000ms[23hours]
I: from 2005-10-29 18:00:00 to 2005-10-30 18:00:00 has 90000000ms[25hours]
I: from 2006-04-01 18:00:00 to 2006-04-02 18:00:00 has 82800000ms[23hours]
I: from 2006-10-28 18:00:00 to 2006-10-29 18:00:00 has 90000000ms[25hours]
I: from 2007-03-31 18:00:00 to 2007-04-01 18:00:00 has 82800000ms[23hours]
I: from 2007-10-27 18:00:00 to 2007-10-28 18:00:00 has 90000000ms[25hours]
I: from 2008-04-05 18:00:00 to 2008-04-06 18:00:00 has 82800000ms[23hours]
I: from 2008-10-25 18:00:00 to 2008-10-26 18:00:00 has 90000000ms[25hours]
I: from 2009-04-04 18:00:00 to 2009-04-05 18:00:00 has 82800000ms[23hours]
I: from 2009-10-24 18:00:00 to 2009-10-25 18:00:00 has 90000000ms[25hours]
I: from 2010-04-03 18:00:00 to 2010-04-04 18:00:00 has 82800000ms[23hours]
I: from 2010-10-30 18:00:00 to 2010-10-31 18:00:00 has 90000000ms[25hours]
I: from 2011-04-02 18:00:00 to 2011-04-03 18:00:00 has 82800000ms[23hours]
I: from 2011-10-29 18:00:00 to 2011-10-30 18:00:00 has 90000000ms[25hours]
I: from 2012-03-31 18:00:00 to 2012-04-01 18:00:00 has 82800000ms[23hours]
I: from 2012-10-27 18:00:00 to 2012-10-28 18:00:00 has 90000000ms[25hours]
I: from 2013-04-06 18:00:00 to 2013-04-07 18:00:00 has 82800000ms[23hours]
I: from 2013-10-26 18:00:00 to 2013-10-27 18:00:00 has 90000000ms[25hours]
I: from 2014-04-05 18:00:00 to 2014-04-06 18:00:00 has 82800000ms[23hours]
I: from 2014-10-25 18:00:00 to 2014-10-26 18:00:00 has 90000000ms[25hours]
I: from 2015-04-04 18:00:00 to 2015-04-05 18:00:00 has 82800000ms[23hours]
I: from 2015-10-24 18:00:00 to 2015-10-25 18:00:00 has 90000000ms[25hours]
I: from 2016-04-02 18:00:00 to 2016-04-03 18:00:00 has 82800000ms[23hours]
I: from 2016-10-29 18:00:00 to 2016-10-30 18:00:00 has 90000000ms[25hours]
I: from 2017-04-01 18:00:00 to 2017-04-02 18:00:00 has 82800000ms[23hours]
I: from 2017-10-28 18:00:00 to 2017-10-29 18:00:00 has 90000000ms[25hours]
I: from 2018-03-31 18:00:00 to 2018-04-01 18:00:00 has 82800000ms[23hours]
I: from 2018-10-27 18:00:00 to 2018-10-28 18:00:00 has 90000000ms[25hours]
I: from 2019-04-06 18:00:00 to 2019-04-07 18:00:00 has 82800000ms[23hours]
I: from 2019-10-26 18:00:00 to 2019-10-27 18:00:00 has 90000000ms[25hours]
I: from 2020-04-04 18:00:00 to 2020-04-05 18:00:00 has 82800000ms[23hours]
I: from 2020-10-24 18:00:00 to 2020-10-25 18:00:00 has 90000000ms[25hours]