NSCalendar获取未来一年

    NSDate *today = [[NSDatealloc]init];

   NSCalendar *gregorian = [[NSCalendaralloc]

                            initWithCalendarIdentifier:NSGregorianCalendar];

   NSDateComponents *offsetComponents = [[NSDateComponentsalloc]init];

    [offsetComponentssetYear:1];

   NSDate * nextYear = [gregoriandateByAddingComponents:offsetComponents

                                                       toDate:todayoptions:0];

    [gregorianrelease];

    [offsetComponentsrelease];

    [todayrelease];