Accrual Balance calculation at the time of Termination

Summary

Accrual balance need to be updated when employee terminate.

Content

Hello All,

We are using Accrual plan.

Details : Front loaded, Yearly time period, Balance will be accrued on 01st Jan of every year.

Now we need to update or recalculate the balance if employee leaves company in between the year.

Example:  Employee Accrual balance at start of year = 96 hours. 

He used some 20 hours in jan and he left the company on 31st march.

Here as per pro rated accrual for 3 months it should be 24. So his balance needs to get updated as 24-20=4 .

Please provide me with formula or setup to achieve this.