iOS 计算某天和当前时间的时间差

/**

*  计算剩余时间

*

*  @param endTime  结束日期

*

*  @return 剩余时间

*/

- (NSString *)getCountDownStringWithEndTime:(NSString *)endTime { NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm"]; NSDate *now = [NSDate date]; NSTimeZone *zone = [NSTimeZone systemTimeZone];//设置时区

NSInteger interval = [zone secondsFromGMTForDate: now];

NSDate *localDate = [now dateByAddingTimeInterval: interval];

endTime = [NSString stringWithFormat:@"%@ 23:59", endTime];

NSDate *endDate = [dateFormatter dateFromString:endTime];

NSInteger endInterval = [zone secondsFromGMTForDate: endDate];

NSDate *end = [endDate dateByAddingTimeInterval: endInterval];

NSUInteger voteCountTime = ([end timeIntervalSinceDate:localDate]) / 3600 / 24;

NSString *timeStr = [NSString stringWithFormat:@"%ld", voteCountTime];

return timeStr;

}