Catchup value Forecast with given Dates

Forecast with given dates.xlsb

Hi Experts,

Need help with forecast value catchup from the given dates.

example:
1. A deal is getting final on 31Jan2024, however its working already started in 01December2023.
2. Now, in books the value of the work to reflect from Feb2024 (since the cutoff date is 15th of every month & here we cannot consider in Jan2024).
3. I need to show catchup value of December2023 and January2024 in February2024 and then onwards.
We get per month value 2,022 from 146,000/13*18%.
need to show the value in feb2024 6,065 = (146,000/13*18%)*3. - Value of dec,jan&feb

Excl.JPG

Thanks!