Apply Compounding Growth Rate Only at Predetermined Time Intervals

Hello everyone

I am scratching my head trying to figure this one out...

I am trying to apply a compounding growth rate to multiple, disparate rows of numbers that represent a monthly timeline. I want the growth rate to hit once a year, but hit at different months for different rows. The growth rate changes each year, so it needs to compound on top of prior year growth rates.

This is difficult to put into words so I have attached an example that should make the goal straightforward to interpret.

Yellow cells are variable inputs, and K2:AO6 is how I would like the end result to look, dynamically, having it adjust as the inputs change.

I have run myself in circles with =MOD(), =DATEDIF, etc. I'm sure this is a piece of cake to someone here. Thank you for any help

Thank you very much. I was able to use this to do exactly what I needed.

I agree that in practice we typically won't have a rate escalation in the first year but would rather have the formula be all encompassing and have the functionality to do so in edge case scenarios.

Agreed on merged cells being a PITA but with some external-facing needs of the file the aesthetics are warranted.

Thank you again for you help