in session
(of an institution, place, etc.) Ready to conduct a meeting or direct an assembly of people.
Court is now in session, all rise!
in-session
This country has come to feel the same when Congress is in session as when the baby gets hold of a hammer. Will Rogers
Congress in session is Congress on public exhibition, whilst Congress in its committee-rooms is Congress at work. Woodrow Wilson
I am maintaining my schedule of commuting to Washington, D.C. each week from Oregon so that I can spend my weekends and days when we are not in session traveling to communities throughout my district. Greg Walden
There is a limitation on debate, which is unlike other bills, for 20 hours, but there is no limitation on amendments. In other words, Republicans if they wanted to, and I suspect they do, could offer literally thousands of amendments and keep Senate in session for weeks and months. Rick Santorum
No man's life, liberty or property are safe while the legislature is in session. Gideon Tucker
Life is now in session. Are you present? John C. Maxwell