获取超过一周的事件时会出现奇怪的错误

Question

当预测设置为获取超过一周的事件时，我收到以下错误：

  

2014-02-18 22：48：04.540 SimpleEKDemo [5283：1803]加载时区时出错   来自文件系统的数据。这是一个严重的问题。日历数据不是   保证准确。

我正在使用Apple Developer网站的SimpleEKDemo项目。我确实按如下方式修改了fetchEvents：

// Fetch events 
- (NSMutableArray *)fetchEvents
{

    //Create the end date components
    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    dateComponents.day = -7; //If set to -6 no error

    NSDate *startDate = [[NSCalendar currentCalendar] dateByAddingComponents:dateComponents
                                                                    toDate:[NSDate date]
                                                                   options:0];
    dateComponents.day = 7;
    NSDate *endDate = [[NSCalendar currentCalendar] dateByAddingComponents:dateComponents
                                                                    toDate:startDate
                                                                   options:0];
    // We will only search the default calendar for our events
    NSArray *calendarArray = [NSArray arrayWithObject:self.defaultCalendar];

    // Create the predicate
    NSPredicate *predicate = [self.eventStore predicateForEventsWithStartDate:startDate
                                                                      endDate:endDate
                                                                    calendars:calendarArray];

    // Fetch all events that match the predicate
    NSMutableArray *events = [NSMutableArray arrayWithArray:[self.eventStore eventsMatchingPredicate:predicate]];

    return events;
}

正在正确获取事件。有什么想法吗？