i would like to calculate time difference between 1st station(Arbeitsplatz1) and last station(Arbeitsplatz19). For example for Value 4B6B831A(wERT-1 Column). It should show me Timestamp difference 04.03.2020 13:54:38 - 04.03.2020 13:49:29 = 00:05:07. I am trying to solve with this logic but it showing me error.(As you can see in screenshot). I am attaching also workbook. If anyone know could you please help me out?