Events can have almost any format. There are a few common types:
Tournaments: where martial combat activities take place Collegia/Symposiums: where you take classes on various topics Arts and sciences fairs: where gentles take A&S projects for feedback and competition Revels: where the populace feasts and dances Many events feature some combination of these activities. Events often last a day (usually a Saturday), a weekend, or in the case of larger wars, a week or more.