vba courses london - Perform deletions on Start up

I want to input a future date into a macro that performes a function when:
1. The workbook is opened, and
2. It recognises that the inputted date is today or has been passed

I guess it would be something like this:
The following written in the "Workbook" module

Public Sub DeleteSheetsDate ()
If Date => #25/12/2007# Then Worksheets("Sheets1") _
And Worksheets("Sheets1").Delete
End if
End Sub

Many thanks
Julian