Help changing config for absence from Days to Hours

I need some help with a piece of configuration, please. We are changing an absence type from Days to Hours (entitlement, take, accumulator, etc.) On the Absence - Country component, Balances page, I want to change that absence from Days to Hours. I can't seem to make the change using a more recent effective date than what's currently there. It won't let me add a row to the grid because it wants the dates in order and it gives me an error unless I just use today's date which is incorrect. I tried to add a new effective dated row