Definition of "weekday"

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

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

   Quotations

   • The Nottingham to Skegness route and Robin Hood line from Nottingham to Mansfield and Worksop will continue with their current weekday patterns; linked to the latter is EMR's commitment to carry out a feasibility study into operating Robin Hood trains to Ollerton.

     2019 October, Tony Miles, Philip Sherratt, “EMR kicks off new era”, in Modern Railways, page 58

2. (Islam) Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday, but not Friday.  examples

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

4. (Judaism) Sunday, Monday, Tuesday, Wednesday, Thursday or Friday, but not Saturday.  examples

(now rare) Any day of the week (Monday through Sunday).