Work day is correct. For example, "Tuesday was just a typically work day for me"

The work day is the part of the day during which a person works. For some people, it may be from 9:00 a.m. to 5:00 p.m. A working day is a day on which people work — i.e., not a day off. For many people, Friday and Saturday are days off, and Monday through Friday are working days. You could also say “a work day” with this meaning.