Te envio parte de un codigo que tengo echo de un relog de inicio y final que me suma los tiempos totales..espero te sirva, si quieres el codigo completo escribeme.
Private Sub cmdini_Click()
If cmdini.Caption = "Final" Then
cmdini.Caption = "Inicio"
Timer1.Enabled = False
Relog.ForeColor = QBColor(2)
HorF = Hor
MinF = Min
SegF = Seg
Lfinal = Format(HorF, "0#") & ":" & Format(MinF, "0#") & ":" & Format(SegF, "0#")
SegT = SegT + Seg
If SegT >= 60 Then
segX = (SegT) - 60
SegT = segX
MinT = MinT + 1
MinT = MinT + Min
Else
MinT = MinT + Min
End If
If MinT >= 60 Then
minX = (MinT) - 60
MinT = minX
HorT = HorT + 1
HorT = HorT + Hor
Else
HorT = HorT + Hor
End If
Tx = Tx + 1
nTx = Tx & " Tiempo " & Lfinal
LTotal = Format(HorT, "0#") & ":" & Format(MinT, "0#") & ":" & Format(SegT, "0#")
List1.AddItem nTx
Seg = 0
Min = 0
Hor = 0
Relog = Format(Hor, "0#") & ":" & Format(Min, "0#") & ":" & Format(Seg, "0#")
Else
Seg = 0
Min = 0
Hor = 0
SegF = 0
MinF = 0
HorF = 0
Relog.ForeColor = QBColor(10)
Lfinal = Format(HorF, "0#") & ":" & Format(MinF, "0#") & ":" & Format(SegF, "0#")
Relog = Format(Hor, "0#") & ":" & Format(Min, "0#") & ":" & Format(Seg, "0#")
cmdini.Caption = "Final"
Timer1.Enabled = True
End If
End Sub