I am trying to keep a log of Flight time and would always like to know what
I've flown within the last 90 days of the current date in several different
modes of flight.
A B C D
1 Date day night NVG
2 2 Sep 06 1.5 2.4
3 15 Sep 06 1.2 2.6
4 22 Sep 06 2.0 4.0

What is the formula to automatically calculate?