Stop today function from updating daily

Hello. This is a pretty standard thing to want to do. The below macro will recognize anytime you select Complete in column N and will put todays date is column O at that row. The date will be static. The code goes in the visual basic editor under the applicable sheet code module. Let me know if you have any questions.

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Target, Range("N:N")) Is Nothing Then
    If Target.Value = "Complete" Then
        Target.Offset(, 1).Value = Date
    End If
End If

End Sub

EDIT: I just noticed that you might need this for multiple columns. If that is the case let me know which columns

EDIT2: this should cover all your columns as you have them represented (even columns)

Private Sub Worksheet_Change(ByVal Target As Range)

If Target.Column Mod 2 = 0 And Cells(1, Target.Column).Value <> "Certification Date" Then
    If Target.Value = "Complete" Then
        Target.Offset(, 1).Value = Date
    End If
End If

End Sub