I have a spread sheet with columns
D= Weekstart (1/1/2006), E=weekend1/7/2006, These are to test a range for
each week and then I=workday 1/3/2006, J=hours (4)

I want to sum all the hours by week into F . All the column data is set up
for the year, but I can't see how to make the formula and test a range of
dates. Do I use sumif or sumproduct?