Get timzone compared to GMT in Android

Question

I need to get the mobile TimeZone comparing to GMT in Android. I only could see one function returns that but as String:

Calendar c = Calendar.getInstance(); 
TimeZone tz = c.getTimeZone();
tz.getID();

This is the description of getID():

Returns the ID of this TimeZone, such as America/Los_Angeles, GMT-08:00 or UTC.

The problem is I need to get that as Integer like +3, -5...

Answer 1

You should be able to calculate the difference based on the TimeZone getOffset() value, see http://developer.android.com/reference/java/util/TimeZone.html#getOffset(long)

Answer 2

public static String getCurrentTimezoneOffset() {

    TimeZone tz = TimeZone.getDefault();  
    Calendar cal = GregorianCalendar.getInstance(tz);
    int offsetInMillis = tz.getOffset(cal.getTimeInMillis());

    String offset = String.format("%02d:%02d", Math.abs(offsetInMillis / 3600000), Math.abs((offsetInMillis / 60000) % 60));
    offset = (offsetInMillis >= 0 ? "+" : "-") + offset;

    return offset;
}