。
What are the visiting hours?
Literal
Visiting-hours [topic-は] how have-become [question-か].
どうなっていますか ('how does it stand / how is it?') is a fixed polite way to ask about the arrangement or current state of something — a schedule, a plan, a situation. Built from どう + なっている + question particle か. Contrast with the blunter 何時ですか ('what time?'), which asks for the time itself.