NSDateFormatter *date = [[NSDateFormatter alloc]init];
[date setDateFormat:@"yyyyMMddHH"];
[date setTimeZone:[NSTimeZone systemTimeZone]];
NSInteger timeSub = [[NSTimeZone systemTimeZone] secondsFromGMT];
NSDate *endD = [endTime dateByAddingTimeInterval:timeSub];
NSTimeInterval interval1 = [startD timeIntervalSince1970];
NSTimeInterval interval2 = [endD timeIntervalSince1970];
NSTimeInterval interval3 = interval2-interval1;