I am using Excel 2000.

I have to create a spreadsheet that calculates the hours used in the last
rolling 12 months.

Col A Col B Col C
Date Hours used Hours in past 12 month period
1-1-07 1.00 1.00
2-15-07 5.00 6.00
2-5-08 8.00 8.00

What formula will I enter to get the amounts in Col. C? Will I have to
enter a different formula for each row in Col. C? Thanks.

Linda