but maybe this will help until somebody (VoG, whisperer, simsy etc) come along.
You can put =today in a cell and the date on which you want the workbook to work in another.
As an example, put =today in A1 and 1/06/05 in B1
In the workbook open event put the follwing
Private Sub workbook_open()
If sheet1.cells(1,1) <> sheet1.cells(1,2) then activeworkbook.close
This will check if today is the date you want the sheet to work and close the sheet if not.