Code for Date filter need to alter!!!

[asyamonique]

Could anybody pls. help me in regards given code below??
I need to change this code for filtering the months instead of dates.Located data on the column B with text value of 12 months 'jan to dec.'

Private Sub CommandButton1_Click()
Sheet2.Select
 
Dim a, i As Long, ii As Long, b(), n As Long, myDate As Date
ListBox2.Clear
With ComboBox4
     If .Value = "" Then Exit Sub
     myDate = DateValue(.Value)
     If WorksheetFunction.CountIf(Range("b:b"), myDate) = 0 Then
          MsgBox "No Entry !"
          Exit Sub
     End If
     a = Range("b1", Range("b" & Rows.Count).End(xlUp)).Resize(, 3).Value
     For i = 1 To UBound(a, 1)
          If a(i, 1) = myDate Then
               n = n + 1: ReDim Preserve b(1 To 3, 1 To n)
               For ii = 1 To UBound(a, 2)
                    b(ii, n) = a(i, ii)
               Next
                   b(1, n) = Format$(a(i, 1), "dd-mmm-yy")
          End If
     Next
End With
With ListBox2
     .ColumnCount = 3
     .ColumnWidths = "60;420;30"
     .Column = b
End With
With Application
    Me.TextBox2.Value = .Sum(.Index(b, 3, 0))
End With
 
End Sub

My Best Regards