How can I automatically subtract a number based on previous 90 days (attendance tracker)

I'm attempting to fix one small issue that I hope one of you gurus can figure out. (latest copy is attached)

At the moment if someone starts the year with 0 points and goes 180 days with perfect attendance, they still have 0 points.
However, those two 90 day periods of perfect attendance do not need to count.

For instance, Jan 1st = 0 points. Perfect attendance for 180 days. Then in August they call off (1 point). They should still only have 1 point until 90 days perfect attendance past the date of the call off in August.

If they start the year with 1 point, go 180 days with perfect attendance, they should have 0 points since the minimum is set to 0(that part works). Now if they get a point in say October their total should be 1 point. Currently it's taking into account the 180 days of perfect attendance at the beginning of the year and subtracting 1 point (it shouldn't do that).