This tip will show the use of TimeZone class to get the time in different time zone.

Java Code:
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;

public class TimeZoneExp {
	public static void main(String[] args) {
		SimpleDateFormat sdf = new SimpleDateFormat("HHmmss");
		TimeZone tz = TimeZone.getTimeZone("GMT");
		Calendar day1 = Calendar.getInstance(tz);
		sdf.setTimeZone(tz);
		String resultTime = sdf.format(day1.getTime());
		System.out.println(resultTime);

	}

}