Using Joda-Time to get UTC offset for a given date and timezone

Question

I have dates in the format 20Jan2013, 08Aug2012 etc, with their own specific timezones. So for example, 20Jan2013 might have a timezone ID of Australia/Melbourne, and 08Aug2

Answer 1

Simple Method for Obtaining Timezone Name and Offset in Hours

public static String getCurrentTimeZoneOffset() {
    DateTimeZone tz = DateTimeZone.getDefault();
    Long instant = DateTime.now().getMillis();

    String name = tz.getName(instant);

    long offsetInMilliseconds = tz.getOffset(instant);
    long hours = TimeUnit.MILLISECONDS.toHours( offsetInMilliseconds );
    String offset = Long.toString( hours );

    return name + " (" + offset + " Hours)";
    // Example: "Mountain Standard Time (-7 Hours)"
}

Couple caveats:

• This gets the default DateTimeZone from JodaTime. You can modify it to accept a specific DateTimeZone that is passed into the method.
• This returns it in a format like "Mountain Standard Time (-7 Hours)" but you can format it as you see fit quite easily.

Hope that helps.

JP