Swinub Pokémon GO Community Day Classic now underway in the Americas and Greenland from 2 p.m. to 5 p.m. local time, evolve Piloswine during the event or up to two hours afterward to get Mamoswine that knows Ancient Power

Please be aware of your surroundings and follow guidelines from local health authorities when playing Pokémon GO. Upcoming events are subject to change. Be sure to follow us on social media, opt in to receiving push notifications, and subscribe to our emails to stay updated.

—The Pokémon GO team

Source: Official Pokémon GO blog