Yes there is a Quiz. Have since found out that it doesn't take place on specific days. The person who runs it does it as and when they are logged on and advertises in the Lobby accordingly. Generally start times are between 19:30 - 20:30.
There’s no specific quiz nights/times. Chatters use the #gamesnight room to create their own quizzes/games.
Anyone can do this at anytime. If you are planning one, feel free to ask a moderator to do a global notice on the site with the time, to advertise so to speak x