format as GMT/UTC time when default timezone is something else

Question

Hey all.

I have a program which needs to run under my local timezone for other reasons, but for one procedure i need to output dates using a SimpleDateFormat in GMT.

what is the tidiest way to do this?

Answer 1

Given that SimpleDateFormat isn't thread-safe, I'd say that the tidiest way is to use Joda Time instead. Then you can create a single formatter (calling withZone(DateTimeZones.UTC) to specify that you want UTC) and you're away:

private static DateTimeFormatter formatter = DateTimeFormat.forPattern(...)
    .withZone(DateTimeZones.UTC);

...

String result = formatter.print(instant);

This has the other benefit that you can use Joda Time elsewhere in your code, which is always a good thing :)

Answer 2

Using the standard API:

TimeZone gmt = TimeZone.getTimeZone("GMT");
DateFormat formatter = DateFormat.getTimeInstance(DateFormat.LONG);
formatter.setTimeZone(gmt);
System.out.println(formatter.format(new Date()));