Create conditional formatting to help with payment dates

Hey,

I'm currently trying to create a conditional formatting formula which highlights my cells based on the dates I'm referencing from another cell with a date from last month. I.e. I want my payment date column to fill with whatever color if todays date is greater than the date from a month ago (today being Oct 8th, I want the cell to fill if the referencing cell has September 1st-7th).

I have some knowledge but everything I've tried with the day, date, today & month formulas have failed. Any help would be greatly appreciated.