weekend=sunday+saterday吗

It depends!
Usually, it means the end of the week, especially the period from Friday evening through Sunday evening.
BUT,if you work six days per week, and you mean the day you are off, then the weekend equals to Sunday.
By the way, you spelled the saturday incorrectly.

拼错了

Saturday + Sunday =周末weekend

你好：
Saturday and Sunday, especially considered as time when you do not work。
比如说：
Are you doing anything nice this weekend ?

weekend一般指周末，在中国就是星期六和星期天。而在外国就是星期天和星期一。所以weekend就是指周末的。另外Saturday打错了。

weekend 是指Saturday
Sunday其实是一周的第一天，而Saturday就是最后一天了

正确！