It is frustrating that it isn't clearly delineated, but you should be fine basing your guess on some reasonable assumptions: schools are busiest during drop off

It is frustrating that it isn't clearly delineated, but you should be fine basing your guess on some reasonable assumptions: schools are busiest during drop off and pickup, with kids out and about near the road, very good chance those times are included in the "restricted hours", possibly the hours in between as well. Public and secular schools are typically not open on weekends, very likely any weekend hour is not restricted. Schools are usually closed during the summer months and for a time during winter break. This can be tricky because school still can have very different schedules and you may not know them if you don't have kid sin school, but again context can help: is the parking lot completely empty? No one around? School's probably not in session, restricted hours probably don't apply. If you were ticketed for speeding in a school zone during morning drop off, I think you'd have a hard time arguing you didn't know it was a restricted time. Maybe during lunch you could make a case, I guess it would depend on the judge you got.