hope this code helps
Select Case Me.program
Case "Monthly"
Me.NextInvoicedate = DateAdd("m", 1, Me.joinDate)
Case "Quarterly"
Me.NextInvoicedate = DateAdd("m", 3, Me.joinDate)
Case "Half yearly"
Me.NextInvoicedate = DateAdd("m", 6, Me.joinDate)
Case "Annually"...