snippet to convert date/time in any timezone to EST

EstTimezone.java

public static Calendar convertTimeToEST(long timeInMillSec) {
    Calendar cal = Calendar.getInstance();
    TimeZone tz = cal.getTimeZone();
    cal.setTimeInMillis(timeInMillSec);
	    
    TimeZone estTz = TimeZone.getTimeZone("America/New_York");
    Calendar estCal = Calendar.getInstance(estTz);
    estCal.setTimeInMillis(timeInMillSec);
    int tzOffset = tz.getOffset(cal.getTime().getTime());
    int estTzOffset = estTz.getOffset(estCal.getTime().getTime());

    estCal.add(Calendar.MILLISECOND, (Math.abs(tzOffset) - Math.abs(estTzOffset)));

    return estCal;
}