Hola!!!
Usa un ciclo:
Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DateTimePicker1.ValueChanged
Dim FechaFinal As DateTime, FechaActual As DateTime
FechaFinal = DateAdd(DateInterval.Day, 5, DateTimePicker1.Value)
For i As Integer = 1 To 7
FechaActual = DateAdd(DateInterval.Day, i, DateTimePicker1.Value)
If FechaActual.DayOfWeek = DayOfWeek.Monday Then
DateTimePicker2.Value = FechaActual
End If
If FechaActual.DayOfWeek = DayOfWeek.Friday Then
DateTimePicker3.Value = FechaActual
End If
Next
End Sub
pd. deberas elejir un domingo
Saludos cordiales