Let me be the first to say,
Welcome to the Forums!
As being an Active Stick Arena player, I can say for one, that the game is always active, depending on your definition of “activity”. To answer your question, (Eastern Time), I see the majority of people get on after 5:00 p.m and it slowly levels off from there. Furthermore, there is also a “Night Lobby” where some people do stay up from 11:00 p.m. to 1:00 a.m. On the weekend, I would say, the activity level does definitely spike from the weekdays.
Nice to hear that you’re from 2006, I am also from 2006! #OldGens