In my experience most advisors try and be available as much as possible, which is not the same thing as 24/7. That’s an entirely different level of service and would come with significant fees, and usually the expectation of significant bookings.

I would assume that most agencies work standard business hours. For me, I will schedule meetings outside of those hours with advance notice, and I will make bookings outside of those hours when possible. But I do have normal human obligations (e.g. doctors appointments, family visits, vacations, flights without WiFi, sleep, etc.) that preclude me from doing work outside of true emergencies.