Of Hand...I don't see anything wrong with your code. It should produce a Date which would be a Thursday of every week up to the EndDate. To test this simply run this code:
Dim iDate As Date, EndDate As Date
Dim zDate As Date
iDate = #2/16/2006#
EndDate = #12/31/2006#
Do While iDate < EndDate
zDate = DateAdd("d", 7, iDate)
MsgBox Format(zDate, "dddd") & " " & zDate
iDate = zDate
The Message Box will display the date for every Thursday up to the EndDate.
The SQL Statement you're using appears to be OK but never the less there may be a issue there. Perhaps a Null where there shouldn't be.
Self Taught In ALL Environments.....And It Shows!