How to hide/unhide columns based on month chosen form a drop down list

[Grev1]

Hi, I am trying to complete an attendance sheet by automatically hiding any column that is not in the month chosen. The drop down list is in cell B6 which is the months of the year (Date formatted to mmmm) and the days of the year are in D6:NE6.
I am trying to use the code below but nothing happens, I am not too familiar with VBA just what I've learned from googling and Youtube. Any help is greatly appreciated.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Range("B6").Value = "January" Then
Columns("D:AH").EntireColumn.Hidden = False
Columns("AI:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "February" Then
Columns("D:AH").EntireColumn.Hidden = True
Columns("AI:BJ").EntireColumn.Hidden = False
Columns("BK:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "March" Then
Columns("D:BJ").EntireColumn.Hidden = True
Columns("BK:CO").EntireColumn.Hidden = False
Columns("CP:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "April" Then
Columns("D:CO").EntireColumn.Hidden = True
Columns("CP:DS").EntireColumn.Hidden = False
Columns("DT:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "May" Then
Columns("D:DS").EntireColumn.Hidden = True
Columns("DT:EX").EntireColumn.Hidden = False
Columns("EY:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "June" Then
Columns("D:EX").EntireColumn.Hidden = True
Columns("EY:GB").EntireColumn.Hidden = False
Columns("GC:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "July" Then
Columns("D:GB").EntireColumn.Hidden = True
Columns("GC:HG").EntireColumn.Hidden = False
Columns("HH:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "August" Then
Columns("D:HG").EntireColumn.Hidden = True
Columns("HH:IL").EntireColumn.Hidden = False
Columns("IM:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "September" Then
Columns("D:IL").EntireColumn.Hidden = True
Columns("IM:JP").EntireColumn.Hidden = False
Columns("JQ:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "October" Then
Columns("D:JP").EntireColumn.Hidden = True
Columns("JQ:KU").EntireColumn.Hidden = False
Columns("KV:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "November" Then
Columns("D:KU").EntireColumn.Hidden = True
Columns("KV:LY").EntireColumn.Hidden = False
Columns("LZ:NE").EntireColumn.Hidden = True
ElseIf Range("B6").Value = "December" Then
Columns("D:LY").EntireColumn.Hidden = True
Columns("LZ:NE").EntireColumn.Hidden = False
Else
Columns("D:NE").EntireColumn.Hidden = False
End If
End Sub

 

[Fluff]

I would recommend a change event, as already mentioned, rather than a selection change. In which case you could use

Private Sub Worksheet_Change(ByVal Target As Range)
   If Target.CountLarge > 1 Then Exit Sub
   If Target.Address(0, 0) = "B6" Then
      Columns("D:NE").Hidden = False
      Select Case Format(Target.Value, "mmmm")
         Case "January"
            Columns("AI:NE").EntireColumn.Hidden = True
         Case "February"
            Columns("D:AH").EntireColumn.Hidden = True
            Columns("BK:NE").EntireColumn.Hidden = True
         Case "March"
            Columns("D:BJ").EntireColumn.Hidden = True
            Columns("CP:NE").EntireColumn.Hidden = True
         Case "April"
            Columns("D:CO").EntireColumn.Hidden = True
            Columns("DT:NE").EntireColumn.Hidden = True
         Case "May"
            Columns("D:DS").EntireColumn.Hidden = True
            Columns("EY:NE").EntireColumn.Hidden = True
         Case "June"
            Columns("D:EX").EntireColumn.Hidden = True
            Columns("GC:NE").EntireColumn.Hidden = True
         Case "July"
            Columns("D:GB").EntireColumn.Hidden = True
            Columns("HH:NE").EntireColumn.Hidden = True
         Case "August"
            Columns("D:HG").EntireColumn.Hidden = True
            Columns("IM:NE").EntireColumn.Hidden = True
         Case "September"
            Columns("D:IL").EntireColumn.Hidden = True
            Columns("JQ:NE").EntireColumn.Hidden = True
         Case "October"
            Columns("D:JP").EntireColumn.Hidden = True
            Columns("KV:NE").EntireColumn.Hidden = True
         Case "November"
            Columns("D:KU").EntireColumn.Hidden = True
            Columns("LZ:NE").EntireColumn.Hidden = True
         Case "December"
            Columns("D:LY").EntireColumn.Hidden = True
      End Select
   End If
End Sub

 

[Fluff]

But that is showing the script not what is actually in the cell.

The image of the sheet below the code images shows that there is a date in B6, rather than text.

 

[Grev1]

Try it like

Select Case Format(Target.Value, "mmmm")

This and changing it to worksheet_change worked! Thank you all so much, this has been wrecking my head for weeks now.

 

[Fluff]

Glad we could help & thanks for the feedback.