NSDate *nowDate = [NSDate date];
NSDateFormatter *dateFomatter = [[NSDateFormatter alloc] init];
dateFomatter.dateFormat = @"yyyy-MM-dd HH:mm:ss";
// 截止时间字符串格式
NSString *expireDateStr = @"2017-04-22 15:33:57";
// 当前时间字符串格式
NSString *nowDateStr = [dateFomatter stringFromDate:nowDate];
// 截止时间data格式
NSDate *expireDate = [dateFomatter dateFromString:expireDateStr];
// 当前时间data格式
nowDate = [dateFomatter dateFromString:nowDateStr];
// 当前日历
NSCalendar *calendar = [NSCalendar currentCalendar];
// 需要对比的时间数据
NSCalendarUnit unit = NSCalendarUnitYear | NSCalendarUnitMonth
| NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
// 对比时间差
NSDateComponents *dateCom = [calendar components:unit fromDate:expireDate toDate:nowDate options:0];
// 差值
NSLog(@"年差额 = %ld, 月差额 = %ld, 日差额 = %ld, 小时差额 = %ld, 分钟差额 = %ld, 秒差额 = %ld", (long)dateCom.year,(long)dateCom.month,(long)dateCom.day,(long)dateCom.hour,(long)dateCom.minute,(long)dateCom.second);
