In an effort to give players more ways to enjoy Pokémon GO, Niantic is trying out a new event called Legendary Lunch Hour.
From 12:00 p.m. to 1:00 p.m. in your local time zone, there will be an increased number of raids to test your battle skills alongside your friends, coworkers, and classmates. The first Legendary Lunch Hour will take place on March 13th.
Niantic hopes to make it a weekly event.
Source: Niantic