How to get timezone by utc offset?

问题

I have the UTC offset -05:00, I want to get timezone names by offset.

ZoneOffset offset = ZoneOffset.of("-05:00");
System.out.println(offset.getId()); //prints -05:00

I want to get the result like this :

America/Chicago
America/Eirunepe
Etc/GMT+5
Mexico/General 
...

I want time zones that are at offset -05:00 right now (not those that may be at another time of year).

回答1:

Yes you can do it, check this out.

final List<ZoneId> timeZoneByUtc = ZoneId.getAvailableZoneIds().stream().map(ZoneId::of)
        .filter(z -> z.getRules().getOffset(Instant.now()).equals(ZoneOffset.ofHours(-5)))
        .collect(Collectors.toList());

回答2:

First determine when is “right now”: use Instant.now() (if you want a consistent answer, call Instant.now() only once).

Then iterate over all available time zones and include those that are at offset -05:00 right now. First get available time zone IDs as strings from ZoneId.getAvailableZoneIds(). For each get the corresponding ZoneId object from ZoneId.of(String). There are different ways to obtain the offset right now. One is yourZoneId.getRules().getOffset(rightNow) (where rightNow is your Instant). This gives you a ZoneOffset object that you can compare to your offset from the question using .equals(Object).

Happy coding.

回答3:

public class Main {

    public static void main(String[] args) {

        TimeZone tz = TimeZone.getTimeZone("GMT-05:00");
        String a[] = TimeZone.getAvailableIDs(tz.getOffset(System.currentTimeMillis()));
        for (int i = 0; i < a.length; i++) {
            System.out.println(a[i]);
        }
    }
}

O/P

America/Atikokan America/Bogota America/Cancun America/Cayman America/Coral_Harbour America/Detroit America/Eirunepe America/Fort_Wayne America/Grand_Turk America/Guayaquil America/Havana ...

来源：https://stackoverflow.com/questions/51045064/how-to-get-timezone-by-utc-offset

标签

java

timezone-offset