Since August 15 is a Catholic feast day (The Assumption of Our Lady), does that mean that certain places will be closed? I wasn't sure if this was what was considered a Catholic "holiday" as mentioned in my RS guidebook.
Shops are closed, everything else is open.
You can look up opening hours for every museum at Munich museums A-Z .
The best course Is to consider everything to be on a Sunday schedule. Most shops are closed and the public transport is on a Sunday schedule.
DJ