I want to generate an autonumber with year month and date format

Public Sub CalculateNewRecordNumber(ByVal record As String)
    Dim data As String() = record.Split("-"c)
    Dim currentDate As DateTime = DateTime.Today
    Dim recordYear As Integer = Integer.Parse(data(0))
    recordYear = Integer.Parse("20" & recordYear)
    Dim recordMonth As Integer = Integer.Parse(data(1))

    If currentDate.Year = recordYear Then

        If currentDate.Month = recordMonth Then
            Dim number As Integer = Integer.Parse(data(2))
            number += 1
            record = recordYear & recordMonth & "-"
            Dim _recNumberOnly As String = number.ToString()

            For i As Integer = 0 To 4 - 1

                If _recNumberOnly.Length = 4 Then
                    Exit For
                Else
                    _recNumberOnly = "0" & _recNumberOnly
                End If
            Next

            record += _recNumberOnly
        Else
            recordMonth += 1
            record = recordYear & recordMonth & "-0001"
        End If
    Else
        recordYear += 1
        record = recordYear & "08-0001"
    End If


End Sub