Event details https://support-leagueoflegends.riotgames.com/hc/en-us/articles/1500001988662
The party begins on 2021-02-04T21:00:00Z , and it won’t stop until 2021-03-09T07:59:00Z . Missions will follow suit, ending March 8th, 2021 at 11:59 PM (PT) , but you’ll have until 2021-03-22T20:00:00Z to spend your party favors…er, Tokens.