Gathering are held every full moon. All four clans meet in peace at the Fourtrees/on the island. A sacred truce from StarClan exists on those night and no blood is to be spilled. The clans meet and the leaders anounce news and the warriors swap tale of recent battles, while the elders discuss how the old times. The leader will pick a group of cats from his/her clan to accompany him/her to the Fourtrees/Island.

If you have any questions, or if I got something wrong, tell me in the comments!