在指定日期后，强制加载宏才能正常显示的代码，请大神指正

liclient

代码如下，如果年份是2018，则运行正常，但是改为2017则报错，我不知道错在哪里


Option Explicit

Private Sub Workbook_BeforeClose(Cancel As Boolean)
If Date < #3/20/2018# Then
    Sheets(9).Activate
    Sheets(9).Visible = -1
    Sheets(9).Activate
    Sheets(1).Visible = 2
    Sheets(2).Visible = 2
    Sheets(3).Visible = 2
    Sheets(4).Visible = 2
    Sheets(5).Visible = 2
    Sheets(6).Visible = 2
    Sheets(7).Visible = 2
    Sheets(8).Visible = 2

Else
    Sheets(9).Activate
    Sheets(9).Visible = 2
    Sheets(9).Activate
    Sheets(1).Visible = -1
    Sheets(2).Visible = -1
    Sheets(3).Visible = -1
    Sheets(4).Visible = -1
    Sheets(5).Visible = -1
    Sheets(6).Visible = -1
    Sheets(7).Visible = -1
    Sheets(8).Visible = -1
End If



ThisWorkbook.Save

End Sub



Private Sub Workbook_Open()

If Date < #3/20/2018# Then
    MsgBox "欢迎使用"
    Sheets(1).Visible = -1
    Sheets(2).Visible = -1
    Sheets(3).Visible = -1
    Sheets(4).Visible = -1
    Sheets(5).Visible = -1
    Sheets(6).Visible = -1
    Sheets(7).Visible = -1
    Sheets(8).Visible = -1

    Sheets(9).Activate

    Sheets(9).Visible = 2


Else
   Sheets(1).Visible = 2
    Sheets(2).Visible = 2
    Sheets(3).Visible = 2
    Sheets(4).Visible = 2
    Sheets(5).Visible = 2
    Sheets(6).Visible = 2
    Sheets(7).Visible = 2
    Sheets(8).Visible = 2

    Sheets(9).Activate

    Sheets(9).Visible = -1

End If


End Sub