'Dim textbox1 As New TextBox With {.Text = "42782,4063949074"}
 
 
Dim dbl As Double, dati As DateTime
 
If Double.TryParse(textbox1.Text, dbl) Then
   dati = DateTime.FromOADate(dbl)  'Double --> Datum/Zeit
   MsgBox("Das Datum ist: " & _
     dati.ToString("dd.MM.yyyy hh:mm:ss")) 'Datum/Zeit --> String
Else
   MsgBox("Es ist kein geeigneter Doublewert gegeben worden")
End If