Rule to prohibit someone from working on a project or in a time sl

Hi

I have a database table where you enter records of people with specific
tasks in certain time slots.
For example:
Record 1: Jim Smith Project A Tues 10-12pm
Record 2: Nancy Jones Project B Wed 2-4pm
Record 3: Nancy Jones Project B Fri 10-12
Record 4: Jim Smith Project A Fri 10-12

Can I create a rule that prohibits entering records of certain people at
specific time slots? For example, you cannot enter Jim Smith for Project A
on Monday at 10-12?

Thank you!

Craig