Private Sub elapsetimer_Tick(sender As Object, _
                e As System.EventArgs) Handles elapsetimer.Tick
 
        lblElapsed.Text = String.Empty
 
        'aktuell angezeigtes Projekt in Projektgrid
        Dim row As DataRow = DirectCast(bs(bs.Position), DataRowView).Row
        Dim projectid As Integer
        If Not Integer.TryParse(row.Item("ID").ToString, projectid) Then Exit _
          Sub
 
        With timetable
            For i As Integer = 0 To .Rows.Count - 1
                'Laufende Zeitmessung
                If IsDBNull(.Rows(i)("Ende")) Then
 
                    'Seit dem Start verstrichene Sekunden in Intervall-Spalte 
                    ' eintragen
                    Dim start As Date = DirectCast(.Rows(i)("Start"), Date)
                    Dim elapsed As New TimeSpan(Now.Ticks - start.Ticks)
 
                    .Rows(i)("Intervall") = elapsed.TotalSeconds
 
                End If
            Next i
        End With
 
        'Intervalle aller abgeschlossenen Arbeitsphasen des Projekts summieren
        Dim projectseconds_total As Integer = _
        Aggregate r As DataRow In timetable _
            Where DirectCast(r("ProjectID"), Integer) = projectid _
            And Not IsDBNull(r("Ende")) _
        Select DirectCast(r("Intervall"), Integer) Into Sum()
 
        'Intervalle aller Arbeitsphasen des Projekts für heute summieren
        'incl. laufende Messung
        Dim projectseconds_today As Integer = _
        Aggregate r As DataRow In timetable _
           Where DirectCast(r("ProjectID"), Integer) = projectid _
           And DirectCast(r("Start"), Date).DayOfYear = Today.DayOfYear _
        Select DirectCast(r("Intervall"), Integer) Into Sum()
 
        'Umwandlung der Sekundensumme in Timespan-Objekt
        Dim ts As New TimeSpan(0, 0, projectseconds_today)
 
        'Formatierte Anzeige mit custom-format
        lblElapsed.Text = ts.ToString("hh\:mm\:ss") 
    End Sub