Tricky question! Employees rewards!

Hello developers
I have employees who get rewarded a certain amount of XP based on their performance every two weeks, all sorted out.

The question is:
I need their reward column on Glide to be cleaned every two weeks so the calculation keeps on, how?

I would love to have it like a switch off/on option named “Done” in front of each one of them so everytime I switch it on the employee reward becomes zero! If I don’t switch it on, it should be called “Leftover”! How?