android - 从当前时区转换为 UTC 减量 2 小时而不是 1 小时

Question

我想将日期从我当前的时区转换为 UTC。

我无法理解结果。

代码:

public static String convertToUTC(String dateStr) throws ParseException
{

    Log.i("myDateFunctions", "the input param is:"+dateStr);

    String uTCDateStr;


    Date pickedDate = stringToDate(dateStr, "yyyy-MM-dd HH:mm:ss");

    Log.i("myDateFunctions", "the input param after it is converted to Date:"+pickedDate);


    TimeZone tz = TimeZone.getDefault();
    Date now = new Date();
    Log.i("myDateFunctions:", "my current Timezone:"+tz.getDisplayName()+" +"+(tz.getOffset(now.getTime()) / 3600000));

    // Convert to UTC
    SimpleDateFormat converter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    converter.setTimeZone(TimeZone.getTimeZone("UTC"));
    uTCDateStr = converter.format(pickedDate);

    Log.i("myDateFunctions", "the output, after i converted to UTC timezone:"+uTCDateStr);

    return uTCDateStr;

}

LogCat 结果是:

03-29 20:31:46.804: I/myDateFunctions(18413): the input param is:2014-04-29 20:00:00
03-29 20:31:47.005: I/myDateFunctions(18413): the input param after it is converted to Date:Tue Apr 29 20:00:00 CEST 2014
03-29 20:31:47.005: I/myDateFunctions:(18413): my current Timezone:Central European Time +1
03-29 20:31:47.005: I/myDateFunctions(18413): the output, after i converted to UTC timezone:2014-04-29 18:00:00

如您所见:我的时区是 CET (GMT+1)

那为什么如果我的输入是 20:00 我会在 18:00 而不是 19:00 回来？

Answer 1

问题是夏令时。 UTC 没有它，如果你有，它会在一年中的部分时间增加 1 小时的差异。