What is the meaning of Weekday?

Any individual day of the week, except those which form the weekend or the single weekly day off; that is:

Monday, Tuesday, Wednesday, Thursday or Friday, but not Saturday or Sunday.
Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday, but not Friday.
Monday, Tuesday, Wednesday, Thursday, Friday, or Saturday, but not Sunday. (e.g. in Vietnam)
Sunday, Monday, Tuesday, Wednesday, Thursday or Friday, but not Saturday.

Monday, Tuesday, Wednesday, Thursday or Friday, but not Saturday or Sunday.

Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday, but not Friday.

Monday, Tuesday, Wednesday, Thursday, Friday, or Saturday, but not Sunday. (e.g. in Vietnam)

Sunday, Monday, Tuesday, Wednesday, Thursday or Friday, but not Saturday.

Any day of the week (Monday through Sunday).

Source: wiktionary.org

See also