计算时间差 - iOS

//结束时间

NSDateFormatter*dateFormatter = [[NSDateFormatteralloc]init];

[dateFormattersetDateFormat:@"yyyy-MM-dd HH:mm:ss"];

NSDate*overdate = [dateFormatterdateFromString:@"2016-09-30 10:10:00"];

NSTimeZone*zone1 = [NSTimeZonesystemTimeZone];

NSIntegerinterva1 = [zone1secondsFromGMTForDate: overdate];

NSDate*endDate = [overdatedateByAddingTimeInterval: interva1];

//获取当前时间

NSDate*date = [NSDatedate];

NSTimeZone*zone2 = [NSTimeZonesystemTimeZone];

NSIntegerinterva2 = [zone2secondsFromGMTForDate: date];

NSDate*currentDate = [datedateByAddingTimeInterval: interva2];

NSLog(@"currentDate=%@ --endDate-%@",currentDate,endDate);

NSTimeIntervaltime=[endDatetimeIntervalSinceDate:currentDate];

NSLog(@"-=========%f",time);