[ticmasta]

hold start & end time in normal DB columns, use business logic for your rule enforcement, have a query to identify rule violation. Maybe add constraints on your warehouse data but I probably wouldn't on the operational DB. I could be convinced to do so for the PoC because it might make sense, but what if you're managing thousands or millions of scheduled "resources" like a chain of libraries, or hotel rooms? What if you need to coordinate "leases"? DB-level is an OK place to start, but also one of the hardest to tease apart when you need to scale.

This is kind of the point of data modeling; you start with an idea, make it all pretty 3rd-normal form, define your projected indices and checks and constraints, then you mess it up a bit where it makes sense or you've had experience in the past.

YMMV