Try this in VBA (Tools-Macro-Visual Basic Editor then select required sheet)

Assuming your date for validation is in A1.

Copy the following code.

=========================================
Private Sub Worksheet_Change(ByVal Target As Range)
If Range("A1") = Date Then
With Cells.Validation
.Delete
.Add Type:=xlValidateTextLength, AlertStyle:=xlValidAlertStop, _
Operator:=xlEqual, Formula1:="0"
.IgnoreBlank = True
.InCellDropdown = True
.InputTitle = ""
.ErrorTitle = "Sheet Expired"
.InputMessage = ""
.ErrorMessage = "Sheet Expired"
.ShowInput = True
.ShowError = True
End With
End If
End Sub
=========================================


Please rate me.

"jorgie" wrote:

I have data that is entered from a report that is done periodically and dont
want users to use the spreadsheet after a specific date (this date is entered
into a header). So I want to be able to look at the current date and compare
it to the header date and if the current date exceeds the header date then
the spreadsheet becomes unusable.