Here this will calculate the UTC time offset from current data in desired timezone.

+(NSTimeInterval)getUTCOffSetIntervalWithCurrentTimeZone:(NSTimeZone *)current forDate:(NSDate *)date  {
    NSTimeZone *utcTimeZone = [NSTimeZone timeZoneWithAbbreviation:@"UTC"];
    NSInteger currentGMTOffset = [current secondsFromGMTForDate:date];
    NSInteger gmtOffset = [utcTimeZone secondsFromGMTForDate:date];
    NSTimeInterval gmtInterval = currentGMTOffset - gmtOffset;
    return gmtInterval;
}