How to correctly write the formula for qlik sense in set analysis?

Question

API

Sorry for the wrong tag

There is a formula like this in measure
count(distinct {<[Date]={">=$(=date(max([Date])-90))<=$(=date(max([Date] )))"}>} [id])

there is a pivot table in by month.
The bottom line is that the result for the last 90 days is displayed in the cell.
those. if October, then we look at the last maximum date - 90 days, we get two dates. We consider everything that fell into this interval. and so on for each month.

but now it doesn't feel right. just takes the interval from the maximum date and counts purely within the month