【Excel】エクセルファイルを日付名で一括コピーするマクロ

Private Sub Workbook_Open()
    UserForm1.Show
End Sub

Private Sub CommandButton1_Click()
  Dim strIn As String
  Dim arr() As String
  Dim extension As String
  Dim originalName As String
  Dim copyName As String
  Dim startArr() As String
  Dim endArr() As String
  
  originalName = "コピーするエクセルファイル名"
  strIn = TextBox1.Value
  If strIn = "" Then
    MsgBox "何も入力されませんでした。"
  Else
    arr = Split(strIn, "/")
    
    startDate = DateSerial(arr(0), arr(1), 1)
    endDate = DateSerial(arr(0), arr(1) + 1, 1) - 1
    
    startArr = Split(startDate, "/")
    endArr = Split(endDate, "/")

    If OptionButton1.Value = True Then
        extension = "xlsm"
    ElseIf OptionButton2.Value = True Then
        extension = "xlsx"
    End If


    If CheckBox1.Value = True Then
        For i = Val(startArr(2)) To Val(endArr(2))
            YMD = Weekday(startArr(0) & "/" & startArr(1) & "/" & i)
            If YMD <> 1 And YMD <> 7 Then
                copyName = Val(startArr(1)) & "." & i
                FileCopy ThisWorkbook.Path & "\" & originalName & "." & extension, ThisWorkbook.Path & "\" & copyName & "." & extension
            End If
        Next
    Else
        For i = Val(startArr(2)) To Val(endArr(2))
            YMD = Weekday(startArr(0) & "/" & startArr(1) & "/" & i)
            copyName = Val(startArr(1)) & "." & i
            FileCopy ThisWorkbook.Path & "\" & originalName & "." & extension, ThisWorkbook.Path & "\" & copyName & "." & extension
        Next
    End If
    
    MsgBox startDate & "から" & endDate & "まで、コピーを作成しました。"
    Unload UserForm1
  End If
End Sub

Private Sub UserForm_Initialize()
    Application.Visible = False
    TextBox1.Value = Year(Date) & "/" & Month(Date) + 1
End Sub