noun
opening (of a room, library, museum, etc.); being open
Refers to a room or facility being open and accessible to people, often used for libraries, museums, or study rooms.
図書館の開室時間は朝9時からです。
The library's opening hours are from 9 a.m.
開室中はいつでもご利用いただけます。
You may use it at any time while it is open.
noun
(organization) being available to take on work
Used for organizations or offices indicating they are open for business or ready to accept tasks.
本日は開室しておりますので、お気軽にお問い合わせください。
We are open today, so please feel free to contact us.