ios怎么推断日期是周末？

- (NSString *)calculateWeek:(NSDate *)date{//计算week数NSCalendar * myCalendar &＃61; [NSCalendar currentCalendar];myCalendar.timeZone &＃61; [NSTimeZone systemTimeZone];NSInteger week &＃61; [[myCalendar components:NSWeekdayCalendarUnit fromDate:date] weekday];NSLog(&＃64;"week : %zd",week);switch (week) {case 1:{return &＃64;"周日";}case 2:{return &＃64;"周一";}case 3:{return &＃64;"周二";}case 4:{return &＃64;"周三";}case 5:{return &＃64;"周四";}case 6:{return &＃64;"周五";}case 7:{return &＃64;"周六";}}return &＃64;"";
}