Calculate next due date

Calculate next due date

Hello Zoho Community,

I need to calculate something. Perhaps you have an idea:

I have a field for a starting date of a contract. e.g. 1.3.2023
I also contract length in month: Renewal every 3 month
Now I want to calculate the next  renewal date. (In this case it would be 01.12.24)

Any idea would be nice.

Best wishes

Niels