Option Explicit
Private WithEvents App As Application
Private Sub Workbook_Open()
Set App = Application
End Sub

Private Sub App_WorkbookBeforeSave(ByVal Wb As Workbook, ByVal SaveAsUI As Boolean, Cancel As Boolean)
With Wb.Sheets(1).PageSetup
.LeftMargin = Application.InchesToPoints(0. 8)
.RightMargin = Application.InchesToPoints(0.4)
.TopMargin = Application.InchesToPoints(0.4)
.BottomMargin = Application.InchesToPoints(0.4)
.HeaderMargin = Application.InchesToPoints(0.2)
.FooterMargin = Application.InchesToPoints(0.2)
.FitToPagesWide = 1
.FitToPagesTall = 1
End With
End Sub