NSCalendar & NSDateComponents - めもめも一ヶ月前の今日を取得するには NSCalendar *calendar = [[NSCalendar currentCalendar]; NSDateComponents *comps = [[[NSDateComponents alloc] init] autorelease]; comps.month = -1; NSDate *date = [calendar dateByAddingComponents:comps toDate:[NSDate date]]; 今月の1日を取得するには NSCalendar *calendar = [[NSCalendar currentCalendar]; unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit; NSDateComponents *comps = [calend
