iphone：找到第4天的日期

Question

我使用NSDateComponents来查找一周中的第4天，第2天的日期

NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc]
                         initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *weekdayComponents = [gregorian components:(NSDayCalendarUnit |
                                                                 NSMonthCalendarUnit |
                                                                 NSYearCalendarUnit |
                                                                 NSWeekCalendarUnit | 
                                                                 NSWeekdayCalendarUnit)
                                                       fromDate:today];
[weekdayComponents setWeekday:4];


NSLog(@"Date at that day was %@",[gregorian dateFromComponents:weekdayComponents]);

但每次输出都是

当天的日期是2011-06-20 18:30:00 +0000

你能帮忙吗？
提前致谢

Answer 1

[weekdayComponents setDay:weekdayComponents.day+ (4-weekdayComponents.weekday)];

至于NSlog输出：NSLog（@“％@”，somedate）以GMT0显示时间，但NSDateComponents的操作考虑了时区，因此2011-06-20 18:30:00 +0000开始于21.06 .2011在你的时区