src/main/java/com/zandero/utils/DateTimeUtils.java
public static long getTimezoneTime(long time, int timezone) {

		Calendar calendar = getCalendar(time);
		int hour = calendar.get(Calendar.HOUR_OF_DAY);

		hour = (hour + timezone) % 24;
		if (hour < 0) {
			hour = 24 + hour;
			calendar.add(Calendar.DAY_OF_MONTH, -1);
		}

		calendar.set(Calendar.HOUR_OF_DAY, hour);
		return calendar.getTimeInMillis();
	}
public static long getTimezoneTime(long time, int timezone) {

		Calendar calendar = getCalendar(time);
		int hour = calendar.get(Calendar.HOUR_OF_DAY);

		hour = (hour + timezone) % 24;
		if (hour < 0) {
			hour = 24 + hour;
			calendar.add(Calendar.DAY_OF_MONTH, -1);
		}

		calendar.set(Calendar.HOUR_OF_DAY, hour);
		return calendar.getTimeInMillis();
	}
Returns time for given time zone
@param time current time
@param timezone time zone (-12 / +12)
@return time in other time zone