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;
}