Change Month range

There’s already a feature that lets us tell the beginning of the month. However, in my case at least, when I choose the 25th I do not mean that my month “starts” 25 days later the actual first day of the month. I mean my months start ~5 days earlier. Meaning, now on the 25th March I want the transactions to be considered for the month “April”, not March. It’s like April starts at 25th March. There could be a way to change this, to define that begging day is not necessarily referenced to the current month, it’s more like the beginning of the next month. Is this making any sense?