Hi!

Try this:

=SUMPRODUCT(--(A2:A100=TODAY()-90),--(L2:L1000),G2:G100)

Adjust ranges to suit.

Note: Sumproduct will not accept whole columns as range arguments: A:A, L:L,
G:G

Biff

"qflyer" wrote in
message ...

I have a pilot logbook in a spreadsheet. Column A is the date of every
flight flown in the past 5 years. Column G is the number of landings
made on each flight. If the flight was at night, the number of hours
(such as 1.2 or 3.6) is entered in column L. If the value in L is 0,
it is assumed the flight was in the day time.

To remain current, I have to make at least 3 landings at night. So I
need a formula that would look at each flight in the past 90 days
(Column A), look to see if the flight was at night (Column L), and then
if the date is within the past 90 days, and the night hours column is
greater than 0, it should total the number of landings (Column G). Can
SUMIF look at multiple ranges or do I need a different formula?

Hope this is clear enough...

Thanks in advance,
Scott


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