Question about using recursive reports but only reclusive until post month

I am working on setting up some recursive data structures to capture the data I need for this instance it charges in a period. We can call this resident's charges. Charges are accumulated until a post date which is most of the time the 21's day of the month with some exceptions.

I have a small web form that lists these days...

The problem I a running into is that I am using JSON get requests to get the data from entrada our software. The issue I am running into is that I am having issues setting up a recursive statement that would label the date as the correct post-month. That I can then run a recursive statement on. Additionally making this harder when I run the get the request the only date I get out of the request is batch last ran or the day its ran.

How would I get around this... for example, a march request would pull fine until the close date on the 21 then after that it would be labeled as April until its close date which is the 14th(list generated).

Has anyone run into a similar issue what did you do to label and replace data to keep it current?