Change day of month, for monthly data tracking.

I would like to change the data usage tracking dates to match my ISP data date. It shows data usage for the month, but it is not the same data cycle as my ISP. For instance my AT&T cycle resets on the 22nd of each month, but the eero resets on the first. It makes it more difficult than it needs to be to try and see if I am being billed for the correct usage.