Hot on the heels of the second Pokémon GO Community Day, the third official Pokémon GO Community Day has been announced to take place on March 25, 2018, between 1 p.m. and 4 p.m. CDT. The upcoming event will feature Bulbasaur with an exclusive move, triple catch XP and three-hour Lures. More details about this event will be announced at a later date, so stay tuned for any updates.
Pokémon GO Community Day
Get out and play together in your local community parks on Pokémon GO Community Day. For just a few hours each month, you can encounter a special Pokémon in the wild. During these hours, there’s a chance to learn a previously unavailable move for that Pokémon or its evolution, as well as earn some Community Day bonuses. Celebrate what it means to be a part of the Pokémon GO community and make new friends along the way!
Note: Fast TMs and Charged TMs will not grant exclusive moves during Community Day. To learn the exclusive move, you must catch or evolve the featured Pokémon during Community Day hours.
Source: Official Pokémon GO events page