獲得一個月后 的日期 該如何實現？

    NSCalendar * calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSCalendarIdentifierGregorian];// 公立
    NSDateComponents * components = [[NSDateComponents alloc]init];
    
    [components setYear: 1];
    [components setMonth: - 1];
    [components setDay: 5]; //設置你需要增加或減少的年、月、日即可獲得新的日期
    
    NSDate * newData = [calendar dateByAddingComponents:components toDate:[NSDate date] options:0];
    NSDateFormatter * dateFormatter = [[NSDateFormatter alloc]init];
    [dateFormatter setDateFormat:@"YY年MM月dd日"];
    NSString * timeString = [dateFormatter stringFromDate:newData];
    
    NSLog(@"更改后的日期是:%@", timeString);