Niantic announced the full details of the Holiday 2020 event on the official Pokémon GO blog. Starting the day after the Galarian Mr. Mime-centric Chill Tunes Event ends, the Holiday 2020 event will run from Tuesday, December 22nd, 2020 at 8 AM through Thursday, December 31st, 2020 at 10 PM local time. They posted the following details: