calculate by date

[bpflyr]

I have posted this before, but I think I have an easier question format.
I have a logbook with hundreds of rows. I need Excel to calculate a specific column based on the previous 90 days total. This calculation will be done on a separate summary worksheet.

How can I get Excel to calculate for the previous 90 days and transfer that data to another worksheet?

Example

Date Flight Time
01-03-05 2.2
03-06-05 1.2
05-02-05 1.6

(and on a separte worksheet page)

Total Flight Time Previous 90 Days: ???

 

[NBVC]

Perhaps:

=SUMPRODUCT(--(Sheet1!A1:A14>=(TODAY()-90)),Sheet1!B1:B14)

replace Sheet1 with actual name of the sheet where the original data is found.
Adjust ranges to suit.

 

[bpflyr]

Thank you for your reply!! However, the formula is just returning a date of 1/0/1900. I need it to calculate a number based on 90 days prior worth of data.

 

[bpflyr]

P.S. I am sorry, I accidentally hit the Report button. Don
t know if this caused any grief or not.

 

[NBVC]

It worked with my test.

Is your date column formatted as Date and is the result column formatted as number?

Book1
	A	B	C	D
12	1/3/2005	2.2	1.6
13	3/6/2005	1.2
14	10/11/2005	1.6
Sheet1

 

[Brian from Maui]

SUMIF should suffice.

=SUMIF(A1:A3,"<"&TODAY()-90,B1:B3)

Change the criteria to suit your needs.