Is your carry permit you get based on that part time employment only valid while you are doing that work?
Or is the permit valid 24/7 anywhere in Maryland (aside from specific places that prohibit guns)
Not sure if you're asking about mine specifically, or about all. Mine, for example (which cites business ownership as my G&S basis), is 24x7 without restrictions. A permit based on a clearance should also come back without time/place restrictions, but will only be considered valid for as long as you maintain that clearance (or, possibly, that specific employment, depending on just how oppressiony the MSP LD was feeling that moment).