I found a server that runs Minecraft events and they are almost always themed around Origins. They do apps for new events and they also have a modded zombie event in the works that is taking a while.
Most events split players into 2 or 4 teams and each team gets a specific origin. The host says it is over a week but from past events it usually ends up being about 4 days.
The next event is free for all and you get to pick your own origin. They also warn that the rules are more lenient than a lot of event servers so people should read the rules first.
