Transforming month names to numbers - vba

Question

I have a userform that askes to which month the data input is applicable. I have used a combibox with jan, feb, mar etc as possible answers.
Now I want to use these answers to refer to a sheet index number Jan is sheets(2), feb = sheets(3) etc.
How do I do this?
Private Sub Userform_Initialize()
'Empty maandbox1
MultiPage1.Value = 0
Maandbox.Value = ""
With Maandbox
.AddItem "Jan"
.AddItem "Feb"
.AddItem "Mar"
'etc
End With
'Set Focus on Monthbox
Maandbox.SetFocus
End Sub
And then something like:
dim ws as worksheet
dim i as integer
i = Monthbox.Value
Set ws = ActiveWorkbook.Worksheets(i + 1)

Answer 1

i = Monthbox.Listindex + 2
should do the trick, since the listindex starts at 0.

Answer 2

You could use MonthName(). It takes a Long value and it returns its month. Thus, 1 is January, 2 is February and etc. To get the first three letters of the month use Left(value, 3):
Public Sub TestMe()
Dim cnt As Long
For cnt = 1 To 12
Debug.Print MonthName(cnt)
Debug.Print Left(MonthName(cnt), 3)
Next cnt
End Sub
In your case:
Dim ws As Worksheet
Dim i As Long
i = Monthbox.Value
Set ws = ActiveWorkbook.Worksheets(Left(MonthName(cnt + 1), 3))

Answer 3

You can use the DateValue function to return a dummy date and pull the integer month number from there:
Dim dt as Date, i as Long
dt = DateValue(Maandbox.Value & " 1," & Format(Now(),"YYYY"))
i = Format(dt, "M") + 1
I usually just set the date to the first of the month. The Format(Now(),"YYYY") simply turns the current day's date into a year to complete the DateValue function parameters. I have found this method flexible because it creates a date that you can now format however else you need it. For instance, if you need the full month description, you now have the option of doing:
RunMonth = Format(dt, "MMMM")
since it's been saved in your variable.