Массив и ошибка

Public Class Form1
    Dim CalM()()() As String
 
 
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If (Button1.Width = 240) Then
            MonthCalendar1.Visible = True
            Button1.Width = 100
            Button1.Height = 50
            Button1.Location = New Point(345, 12)
            Button1.Font = New Font(Button1.Font.Name, 8)
            Button1.Text = "Скрыть календарь"
            Label1.Visible = True
 
        Else
            MonthCalendar1.Visible = False
            Button1.Width = 240
            Button1.Height = 87
            Button1.Location = New Point(267, 287)
            Button1.Font = New Font(Button1.Font.Name, 20)
            Button1.Text = "Открыть календарь"
            Label1.Visible = False
        End If
 
    End Sub
 
 
 
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        MonthCalendar1.Location = New Point(153, 173)
        MonthCalendar1.Width = 500
        MonthCalendar1.Height = 311
        Button2.Visible = False
        Button1.Visible = True
        Label1.Text = "Нажмите на дату, для перехода к заметкам"
        TextBox1.Visible = False
        Button3.Visible = False
    End Sub
 
    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        CalM(MonthCalendar1.SelectionStart.Day)(MonthCalendar1.SelectionStart.Month)(MonthCalendar1.SelectionStart.Year) = TextBox1.Text
    End Sub
 
    Private Sub MonthCalendar1_DateSelected(sender As Object, e As DateRangeEventArgs) Handles MonthCalendar1.DateSelected
        MonthCalendar1.Width = 164
        MonthCalendar1.Height = 460
        MonthCalendar1.Location = New Point(3, 69)
        Button2.Visible = True
        Button1.Visible = False
        Label1.Text = "Здесь вы можете сделать заметки на день"
        TextBox1.Visible = True
        Button3.Visible = True
 
        If CalM(MonthCalendar1.SelectionStart.Day)(MonthCalendar1.SelectionStart.Month)(MonthCalendar1.SelectionStart.Year) <> "" Then ' На этой строчке вылетает ошибка
            TextBox1.Text = CalM(MonthCalendar1.SelectionStart.Day)(MonthCalendar1.SelectionStart.Month)(MonthCalendar1.SelectionStart.Year)
        End If
    End Sub
End Class

Dim CalM(31, 12, 2099) As String 'указываем сразу размерность массива

CalM(MonthCalendar1.SelectionStart.Day)(MonthCalendar1.SelectionStart.Month)(MonthCalendar1.SelectionStart.Year)

CalM(MonthCalendar1.SelectionStart.Day, MonthCalendar1.SelectionStart.Month, MonthCalendar1.SelectionStart.Year)

   CalM(MonthCalendar1.SelectionStart.Day, MonthCalendar1.SelectionStart.Month, MonthCalendar1.SelectionStart.Year) = TextBox1.Text
            Dim fw As StreamWriter
            Dim ReadString As String
            Try
 
                fw = New StreamWriter("C:\Test1.txt", False)
                ReadString = MonthCalendar1.SelectionStart.Day
                fw.WriteLine(ReadString)
                ReadString = MonthCalendar1.SelectionStart.Month
                fw.WriteLine(ReadString)
                ReadString = MonthCalendar1.SelectionStart.Year
                fw.WriteLine(ReadString)
                ReadString = TextBox1.Text
                fw.WriteLine(ReadString)
 
            Finally
 
                fw.Close()
            End Try

Public Sub saveSettings()
    Dim fs As New FileStream("settings.dat", FileMode.Create, FileAccess.Write, FileShare.ReadWrite)
    Dim DD As New Dictionary(Of Integer, Dictionary(Of Integer, Dictionary(Of Integer, String)))
    Dim bf As New BinaryFormatter
    For i = 0 To CalM.GetLength(0) - 1
        Dim MM As New Dictionary(Of Integer, Dictionary(Of Integer, String))
        For i1 = 0 To CalM.GetLength(1) - 1
            Dim YYYY As New Dictionary(Of Integer, String)
            For i2 = 0 To CalM.GetLength(2) - 1
                If CalM(i, i1, i2) <> "" Then YYYY.Add(i2, CalM(i, i1, i2))
            Next
            MM.Add(i1, YYYY)
        Next
        DD.Add(i, MM)
    Next
    bf.Serialize(fs, DD)
    fs.Close()
End Sub
 
Public Sub loadSettings()
    Dim DD As New Dictionary(Of Integer, Dictionary(Of Integer, Dictionary(Of Integer, String)))
    Dim fs As New FileStream("settings.dat", FileMode.Open, FileAccess.Read, FileShare.Read)
    Dim bf As New BinaryFormatter
    DD = bf.Deserialize(fs)
    For Each i In DD.Keys
        Dim MM As Dictionary(Of Integer, Dictionary(Of Integer, String)) = DD(i)
        For Each i1 In MM.Keys
            Dim YYYY As Dictionary(Of Integer, String) = MM(i1)
            For Each i2 In YYYY.Keys
                CalM(i, i1, i2) = YYYY(i2)
            Next
        Next
    Next
    fs.Close()
End Sub