Attendees at the solstice (either all or many) bring content to be used, tagged with where in the arc it goes (light, twilight, night or morning).
The organizer creates a preliminary schedule, talking to contributors as needed.
Put the preliminary schedule into a form that’s easy to reorder. This could be a Google Doc displayed via data projector or sticky notes along a wall (write large and in sharpie).
When people bring last-minute content, insert it somewhere appropriate. Don’t rethink the order from scratch. Even if this results in a suboptimal total ordering, it’s not worth the time.
Then go over the entire proposed schedule with everyone and make sure everybody’s ok with it. Make changes as needed.
Or, if there’s a general consensus that the room trusts you and everybody wants to start, just go ahead with the schedule as is.
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