Double click on thisworkbook object in VBA project and open the code. Then find the Sub Workbook_Open and use the code below..
'Assume you dont want to show sheet1
Private Sub Workbook_Open()
If Sheet1.Cells(1, 1) < Now() Then
Close False
Else
'This part avoid using sheet1 if user opens the workbook by clicking Disable Macros. So you need to set Sheet1.Visible property in Propertie window to 2 (xlSheetVeryHidden)
Sheet1.Visible = xlSheetVisible
End If
End Sub
'To make sheet1 xlVeryHidden before closing workbook (after making some changes etc)
Private Sub Workbook_BeforeClose(Cancel As Boolean)
Sheet1.Visible = xlSheetVeryHidden
End Sub
Or some other ways like protecting and unprotecting sheets in code with this way.
regards
