Imports System

Imports System.Globalization

Public Module Module1

    Public Sub Main()

        Dim enabler as string = WriteEnabler(new Date(2021, 2, 28))

        Console.WriteLine(enabler)

        Console.WriteLine(CheckEnabler(enabler).ToString("dd/MM/yyyy"))

    End Sub

    Public Function WriteEnabler(d as date) As String

        Dim sEnabler As String

        Dim dEnabler As Date

​

        dEnabler = d.AddDays(17)

        dEnabler = dEnabler.AddMonths(3)

        dEnabler = dEnabler.AddYears(112)

        dEnabler = dEnabler.AddDays(60)

        dEnabler = dEnabler.AddDays(30)

​

        sEnabler = dEnabler.ToString("dd/MM/yyyy")

​

        sEnabler = sEnabler.Replace("1", "e")

        sEnabler = sEnabler.Replace("2", "a")

        sEnabler = sEnabler.Replace("3", "c")

        sEnabler = sEnabler.Replace("4", "d")

        sEnabler = sEnabler.Replace("5", "@")

        sEnabler = sEnabler.Replace("6", "!")

        sEnabler = sEnabler.Replace("7", "g")

        sEnabler = sEnabler.Replace("8", "h")

        sEnabler = sEnabler.Replace("9", "$")

        sEnabler = sEnabler.Replace("0", "j")

​

        sEnabler = sEnabler.Replace("/", "0p1")

​

        Return sEnabler

    End Function

​

    Public Function CheckEnabler(ByVal enabler As String) As Date

        Dim sEnabler As String

        Dim dEnabler As Date = New Date(1990, 1, 1)

​

        sEnabler = enabler

​

        sEnabler = sEnabler.Replace("0p1", "/")

​

        sEnabler = sEnabler.Replace("e", "1")

        sEnabler = sEnabler.Replace("a", "2")

        sEnabler = sEnabler.Replace("c", "3")

        sEnabler = sEnabler.Replace("d", "4")

        sEnabler = sEnabler.Replace("@", "5")

        sEnabler = sEnabler.Replace("!", "6")

        sEnabler = sEnabler.Replace("g", "7")

        sEnabler = sEnabler.Replace("h", "8")

        sEnabler = sEnabler.Replace("$", "9")

        sEnabler = sEnabler.Replace("j", "0")

​

        Try

            dEnabler = Date.Parse(sEnabler, new CultureInfo("en-GB"))

            dEnabler = dEnabler.AddDays(-60)

            dEnabler = dEnabler.AddYears(-112)

            dEnabler = dEnabler.AddMonths(-3)

            dEnabler = dEnabler.AddDays(-17)

        Catch ex As Exception

        End Try

​

        Return dEnabler

    End Function

End Module