Question

I am trying to obtain a simple conversion from one time zone into another using Java Date and Calendar. I am trying to run the following code

    Calendar instance = Calendar.getInstance(TimeZone.getTimeZone("Europe/London"));
    Date date = instance.getTime();
    System.out.println(date);

    GregorianCalendar instance2 = new GregorianCalendar(TimeZone.getTimeZone("Europe/Athens"));
    instance2.setTime(instance.getTime());
    System.out.println(instance2.getTime());

but that still returns the same date, rather than +1 hour… The whole problem seems trivial but i cannot find any simple answer to this. Thanks in advance for your help.

Answer 1

When you print the date using System.out.println(date); or System.out.println(instance2.getTime());, the Date returned by instance2.getTime() is TimeZone independent and always prints the date in local timezone.

Instead you may want to use DateFormat/SimpleDateFormat:

  DateFormat formatter= new SimpleDateFormat("MM/dd/yyyy HH:mm:ss Z");
  formatter.setTimeZone(TimeZone.getTimeZone("Europe/London"));
  System.out.println(formatter.format(date));

  formatter.setTimeZone(TimeZone.getTimeZone("Europe/Athens"));
  System.out.println(formatter.format(instance2.getTime()))