NSCalendar的时区不正确

Question

我正在尝试使用指定的时区名称获取日期，例如“America / New_York”。出于某种原因，当我选择正确的时区“America / Chicago”时，它会显示正确的时间（例如，下午9:41）。然而，当我选择纽约时，它应该显示一小时（预计晚上10点41分），但我比我当前时间晚了一小时（我得到的结果：晚上8点41分）。

- (NSDate*)dateFromTimezone:(NSTimeZone*)timezone
{
    timezone = ( timezone == nil ? [NSTimeZone timeZoneWithName:CUSTOMTIMEZONE] : timezone );

    NSDate * date = [NSDate date];

    NSCalendarUnit units = NSYearCalendarUnit | NSMonthCalendarUnit | NSWeekCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;

    NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    [gregorian setTimeZone:timezone];
    [gregorian components:units fromDate:date];

    NSDateComponents* dateComponents = [[NSCalendar currentCalendar] components:units fromDate:date];
    [dateComponents setTimeZone:timezone];
    [dateComponents setCalendar:gregorian];

    return [gregorian dateFromComponents:dateComponents];
}