NSDateComponent小时不正确

搞不懂为什么我用NSDateComponent修改NSDate的小时就会出错：

NSDateComponent components = [calendar components:  (NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit) fromDate:today];

[components setMinute:myMinute];
[components setHour:7];

NSDate *myNewDate = [calendar dateFromComponents:components];
NSLog(@"%@",myNewDate);

这样之后NSlog就变成：

2012-12-08 06:00:00 +0000

差了一个小时，我设置的其实是7点。请高手帮忙解决一下。谢谢！

是时区的问题：

用[components setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];

映射到你的时间设置：

int main(int argc, char *argv[]) {
@autoreleasepool {
    NSDate *today = [NSDate date];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:  (NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit) fromDate:today];

    [components setMinute:50];
    [components setHour:7];
    [components setTimeZone:[NSTimeZone timeZoneForSecondsFromGMT:0]];

    NSDate *myNewDate = [calendar dateFromComponents:components];
    NSLog(@"%@",myNewDate);
}
}