Find out the time in the time zone I need?

Question

Java

How can I find out the current time in the time zone I need? Or rather UTC-0?

Answer 1

We use the SimpleDateFormat class:

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
format.setTimeZone(TimeZone.getTimeZone("UTC"));
Date date = format.parse("2015-01-23T09:10:00");

Answer 2

in java.util.Date the time is stored in GMT, but using toString() adds the default TimeZone from the JVM settings see java.util.Date#toString and carefully java.util.Date#normalize. To get java.util.Date corrected:

Calendar c = Calendar.getInstance();
    TimeZone z = c.getTimeZone();
    int offset = z.getRawOffset();
    if(z.inDaylightTime(new Date())){
        offset = offset + z.getDSTSavings();
    }
    int offsetHrs = offset / 1000 / 60 / 60;
    int offsetMins = offset / 1000 / 60 % 60;
    c.add(Calendar.HOUR_OF_DAY, (-offsetHrs));
    c.add(Calendar.MINUTE, (-offsetMins));

   return с.getTime();

Answer 3

Calendar calendar = Calendar.getInstance(TimeZone)
The calendar will just have the current time in the desired timezone, and then you can do anything with this calendar, for example, get a Long or Date representation.
TimeZone is also easy to get TimeZone.getTimeZone(ID), ID - zone identifier string