Even if you select both, you will only ever be selected for one of them. For both runs, the days are as follows:
Day 01 Evening - Arrival and check in.
Day 02 - Workshops and Game Start
Day 03 (Saturday) - Game End in the Evening
Day 04 - Cleanup and Leave.
As a note - all written materials for both runs will only be available in english, even though game language for the german run will be german.