timestr

-(void)timeStr

{

    NSDate *date = [NSDate date];

    NSInteger unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;

    NSCalendar *currentCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];

    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];

    formatter.dateFormat = @"yyyy.MM";

    NSDateComponents *currentComps = [currentCalendar components:unitFlags fromDate:date];

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

    [resultComps setYear:[currentComps year]];

    [resultComps setMonth:[currentComps month]];

    [resultComps setWeekday:[currentComps weekday]];

    NSInteger mMonth = [currentComps month];

    for(int i =3;i>-1;i--){

        NSInteger uMonth = mMonth - i;

        [resultComps setMonth:uMonth];

        NSDate *returnDate = [currentCalendar dateFromComponents:resultComps];

        NSString *returnStr = [formatter stringFromDate:returnDate];

        NSLog(@"%@",returnStr);

    }

    

}

 

2月份的   30日   =  3月份，我日错了