I need to create a target, that is based on the number of weeks in a given month, with a target of 1 per week, so that I can achieve conditional formatting on my table.
Example: Feb '22 has 4 weeks, so a target of 4, whereas March '22 has 5 weeks, so needs a target of 5.
Extending what Bo_Bozo has said, this may even vary year to year, based on financial calendar, leap years, etc.
Once that is determined, I would look at a solution in the universe with a date dimension / calendar table to support your reporting requirements. While this assumes that you have access to the underlying database to create (or simply enhance) a calendar table, it will provide you with a far more powerful and robust solution that will perform better than putting the heavy lifting into the report (which will then need to be replicated in multiple reports).