NSDate 获取某个日期之前的日期

- (void)viewDidLoad

{

    [super viewDidLoad];

    

    //当前日期

    NSDate *currentDate = [NSDate date];

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

    

    //当前日期之前或是之后的日期

    NSDate *priousOrLaterDate = [self getPriousorLaterDateFromDate:currentDate withMonth:1 andDays:1];

    NSLog(@"priousOrLaterDate = %@",priousOrLaterDate);

}

-(NSDate *)getPriousorLaterDateFromDate:(NSDate *)date withMonth:(int)month andDays:(int)days

{

    //日期元件

    NSDateComponents *comps = [[NSDateComponents alloc] init];

    [comps setMonth:month];

    [comps setDay:days];

    

    //创建格林日历

    NSCalendar *calender = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

    

    //在当前的时间通过加时间元件得到新的日期

    NSDate *mDate = [calender dateByAddingComponents:comps toDate:date options:0];

  

    return mDate;

}

输入结果：

2014-03-07 11:16:33.620 NSDate_demo[868:a0b] currentDate = 2014-03-07 03:16:33 +0000

2014-03-07 11:16:33.622 NSDate_demo[868:a0b] priousOrLaterDate = 2014-04-08 03:16:33 +0000