Help with if statement with dates

Ok here is the deal. I have a company, I have several employees and i have made a spreadsheet for each.

i have a invoice number column and date column and profit column for each job that they do. they may do several jobs in one day. what i want to know is how much they make total for the week. so in a separate column i want a weekending "such and such date" profit total

get what im saying?

then i can have this for each person then i can just add up each persons week ending column to see how much i have made for this week. but i only what it to add up the numbers in a set range of dates.

for instance in the week ending 9/4/09 column it should only add profits that go from dates aug 30 to sept 4. and in weekending column 9/11/09 it should only add up profits corresponding to dates between 9/7/09 and 9/11/09

get what im saying?? ill post tiny sample if fake spreadsheet. 07 version

IMO, you will better served by using a single worksheet to hold all data and using a Pivot Table to calculate weekly, monthly, yearly, etc. totals

If you enter only the date ending in E2 (i.e. 9/4/2009, etc) then in E3:

=SUMIF($C$3:$C$9,">"&E2-7,$D$3:$D$9)-SUMIF($C$3:$C$9,">"&E2,D3:D9)

copied across... adjust ranges to suit.