在iPhone日历中撰写活动的时间问题

Question

我想在iPhone的默认日历中写活动，但我面临时差问题，我正在开始日期18-02-2014 08:00 PM和结束日期25-02-2014 11:30 PM我正在使用但它是写作开始日期18-02-2014 12:00 PM和结束日期25-02-2014 12:30 PM。我不知道我错在哪里。我怎么能在同一时间写它。< / p>

-(void)writeEventwithTitle:(NSString*)aTitle startDate:(NSDate*)strtDate endDate:(NSDate*)ndDate{
    _eventStore = [[EKEventStore alloc] init];
    [_eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError* error){
        if (!granted) {
            return ;
        }
       EKEvent *event = [EKEvent eventWithEventStore:_eventStore];
        event.title = aTitle;
        event.startDate = strtDate;
        event.endDate = ndDate;
        [event setCalendar:[_eventStore defaultCalendarForNewEvents]];
        NSError* err;

        [_eventStore saveEvent:event span:EKSpanFutureEvents commit:YES error:&err];
    }];
}
-(void)startWritingEvent{
    for (int i = 0 ; i < [_eventArray count]; i++) {
        id dict= [_eventArray objectAtIndex:i];
        NSString* eventTitle = [dict objectForKey:Title];
        NSDictionary* eventBeginArray = [dict objectForKey:EventBegin];

        NSDate* startDate = [self dateFromDate:[eventBeginArray objectForKey:StartDate] andTime:[eventBeginArray objectForKey:StartTime]];
         NSDate* endDate = [self dateFromDate:[eventBeginArray objectForKey:EndDate] andTime:[eventBeginArray objectForKey:EndTime]];

        [self writeEventwithTitle:eventTitle startDate:startDate endDate:endDate];

    }
}
-(NSDate*)dateFromDate:(NSString*)date andTime:(NSString*)time{
    NSString *eventDttm = [[NSString alloc] init];
    eventDttm = [NSString stringWithFormat:@"%@ %@",date,time];
    NSDateFormatter* dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"dd-MM-yyyy HH:mm a"];
    [dateFormatter setTimeZone:[NSTimeZone systemTimeZone]];
    //conversion of NSString to NSDate
     NSDate *dateFromString = [[NSDate alloc] init];
    dateFromString = [dateFormatter dateFromString:eventDttm];

    return dateFromString;
}