A make-up event for Snover Spotlight Hour is coming to Pokémon GO players in select timezones due to an error in the initial hour's run.
Niantic announced the make-up event for Snover Spotlight Hour in Pokémon GO on the game's official blog:.
Due to an issue that occurred during Snover Spotlight Hour, we're holding a regional makeup event on Monday, January 11, 2020, from 6:00 p.m.
Tuesday, January 12, 2021: Drifloon will be in the spotlight, and you'll earn twice the XP for catching Pokémon.