Allocation of days and not %


I have a task that starts on 2020/03/02 and ends on 2020/03/06. The duration is 5T. I would now like to allocate X days (X<5), not %, to the employee. During this period he should work 2 days. I want to enter this amount explicitly in a cell. How does this work? Thank you very much in advance for your help.

Thank you and have a good day,