So: 

opening_hours=Mo, We 08:00-13:00; Tu, Th 08:00-13:00,14:00-17:30; Fr 08:00-12:00; Sa 08:00-12:00 open "nur Terminkunden"; We[3] closed; Sa[1] closed; PH offclosed; PH off

https://openingh.openstreetmap.de/evaluation_tool/ hilft.