NSDate计算时间差

// 时间1

NSDate *date1 = [NSDatedate];

NSTimeZone *zone1 = [NSTimeZonesystemTimeZone];

NSInteger interval1 = [zone1 secondsFromGMTForDate:date1];

NSDate *localDate1 = [date1 dateByAddingTimeInterval:interval1];

// 时间2

NSDate *date2 = [NSDatedate];

NSTimeZone *zone2 = [NSTimeZonesystemTimeZone];

NSInteger interval2 = [zone2 secondsFromGMTForDate:date2];

NSDate *localDate2 = [date2 dateByAddingTimeInterval:interval2];

// 时间2与时间1之间的时间差（秒）

double intervalTime = [localDate2 timeIntervalSinceReferenceDate] - [localDate1 timeIntervalSinceReferenceDate];

NSInteger seconds = lTime % 60;

NSInteger minutes = (lTime / 60) % 60;

NSInteger hours = (lTime / 3600);

NSInteger days = lTime/60/60/24;

NSInteger month = lTime/60/60/24/12;

NSInteger years = lTime/60/60/24/365;