The way I interrupt it...

Today I want to fly... Within the last preceding 90 days (dates) I must have made 3 landings within that period. So as long as I have 3 landings within those previous 90 days, I am legal to fly on the 91st day (today)

Since we don't log the precise time of landings, we are dealing with dates. Therefore, today's date can not be used towards the preceding dates as it is not in the past.