Public Function FindNextPartyDate() As Date
 
        'Static: lokal deklarierte Liste bleibt zwischen 
        '        den Aufrufen erhalten
        Static PartyDates As List(Of DateTime)
 
        If PartyDates Is Nothing Then
            'Beim ersten Aufruf:
            'Liste erstellen und mit üblichen Party-Terminen füllen
            '(Berliner Version: Regionale Abweichungen denkbar)
            PartyDates = New List(Of DateTime)
            Dim start As Long = New Date(Today.Year, 1, 1).Ticks
            Dim ende As Long = New Date(Today.Year + 1, 12, 31).Ticks
 
            For i As Long = start To ende Step TimeSpan.TicksPerDay
                Dim dt As DateTime = New DateTime(i)
 
                With dt
                    If .DayOfWeek = DayOfWeek.Monday Or _
                       .DayOfWeek = DayOfWeek.Sunday Or _
                       .DayOfWeek = DayOfWeek.Saturday Or _
                       .DayOfWeek = DayOfWeek.Friday Then
                        PartyDates.Add(dt)
                    End If
                End With
            Next i
        End If
 
        Dim mindiff As Long = Long.MaxValue
        Dim NextPartyDate As DateTime = Nothing
        Dim diff As Long
        For i As Integer = 0 To PartyDates.Count - 1
            diff = PartyDates(i).Date.Ticks - Today.Date.Ticks
            'Die nächste Party findet in der Zukunft statt
            If diff > 0 AndAlso diff < mindiff Then
                mindiff = diff
                NextPartyDate = PartyDates(i)
            End If
        Next i
        Return NextPartyDate
    End Function

 Private Function DaysLived(ByVal birthday As Date) As Integer
 
    Return (Today.Date - birthday.Date).Days
 
 End Function

 Private Function GetPartyDay(ByVal birthday As Date, _
          ByVal Days As Integer) As Date
 
    Return birthday.Date.AddDays(Days)
 End Function