Imports System

Imports Microsoft.VisualBasic               

​

Public Module Module1

    Public Sub Main()

        Dim x as string

        x = CalculatePaymentDue("PaidinAdvance","20 January 2017")

        Console.WriteLine(x)

    End Sub

​

​

​

'To calculate payment due

Function CalculatePaymentDue(byVal v_PaymentDue as String, _

byVal v_InvoiceDate as Date) as String

    Dim strPaymentDue as String =""

    Dim strPaymentDueTemp as String

    Dim intWorkDays as integer

    Dim intActualDays as integer

    Dim intNumDaysToCount as integer

    Dim intDay as integer

​

    If Len(v_PaymentDue) < 3 Then                     'No suffix

        'Calculate Payment Due Date

        If v_PaymentDue = "20" Then                         'If 20

            strPaymentDue = "Payment is due by " & Format(DateAdd("y", 20, v_InvoiceDate), "dd MMMM yyyy")

        ElseIf v_PaymentDue = "14" Then                     'If 14

            strPaymentDue = "Payment is due by " & Format(DateAdd("y", 14, v_InvoiceDate), "dd MMMM yyyy")

        ElseIf v_PaymentDue = "30" Then                     'If 30

            strPaymentDue = "Payment is due by " & Format(DateAdd("y", 30, v_InvoiceDate), "dd MMMM yyyy")

        ElseIf v_PaymentDue = "21" Then                     'If 21

            strPaymentDue = "Payment is due by " & Format(DateAdd("y", 21, v_InvoiceDate), "dd MMMM yyyy")

        ElseIf v_PaymentDue = "7" Then                     'If 7

            strPaymentDue = "Payment is due by " & Format(DateAdd("y", 7, v_InvoiceDate), "dd MMMM yyyy")

        End If

    ElseIf v_PaymentDue = "NONE" Then           

        strPaymentDue="Payment Now Due"

    ElseIf v_PaymentDue = "PayonReceipt" Then           

        strPaymentDue="Payment due on receipt of services"

    ElseIf v_PaymentDue = "PaidinAdvance" Then              

        strPaymentDue="Paid in advance"

​

    ElseIf (Len(v_PaymentDue) > 2) Then  

        If Len(v_PaymentDue) = 3 Then   'If Suffix

            intNumDaysToCount = Left(v_PaymentDue, 1) + 0

        ElseIf Len(v_PaymentDue) = 4 Then

            intNumDaysToCount = Left(v_PaymentDue, 2) + 0

        End If

        If Right(v_PaymentDue, 2) = "wd" Then   'If wd

            intWorkDays = 0

            intActualDays = 0

            strPaymentDueTemp = v_InvoiceDate 

​

            Do While intWorkDays < intNumDaysToCount 

​

                strPaymentDueTemp = DateAdd("y", 1, strPaymentDueTemp)

                intDay = Weekday(strPaymentDueTemp)

​

                If ((intDay > 1) And (intDay < 7)) Then

                    intWorkDays = intWorkDays + 1

                End If

                intActualDays = intActualDays + 1

​

            Loop

            strPaymentDue = "Payment is due by " & CStr(Format(DateAdd("y", intActualDays, v_InvoiceDate), "dd MMMM yyyy"))

        ElseIf ((Right(v_PaymentDue, 2) = "th") Or (Right(v_PaymentDue, 2) = "st") Or (Right(v_PaymentDue, 2) = "nd") Or (Right(v_PaymentDue, 2) = "rd")) Then              'If th

​

                                                strPaymentDueTemp = DateAdd("M", 1, v_InvoiceDate)

            strPaymentDue = "Payment is due by " & CStr(intNumDaysToCount) & " " & Format(DateAdd("M", 1, v_InvoiceDate), "MMMM") & " " & Format(DateAdd("M", 1, v_InvoiceDate), "yyyy")

​

        End If

​

    End If

        return strPaymentDue

End Function

​

End Module