Accrual rate for colleagues

Hi everyone,

I volunteered to create a database for HR but cannot seem to find a function to calculate different accrual rates for different employees. The accrual rate is in hours, and the accrual rate happens every pay period (we have 24 pay periods). Is there a function out there that can automatically calculate the accrual rate for us? I have attached what I have so far. HR wants the Accrued hours to automatically generate each week without manual input (like what I have right now). I setup the spreadsheet so that the hours taken in the purple will automatically deduct from the yellow columns so that all colleagues know how much vacation time they have.

Thanks in advance!

-Jenny