Co-developer Niantic, which announced the community day details Wednesday, holds these type of events regularly to entice players to spend more time on its other augmented reality game, Pokemon Go. They last for a few hours and give players free loot while improving certain items in order to advance in the game faster.
The firstcommunity day will run from 11 a.m. to 2 p.m. PT on July 20 for players in the Americas and Greenland. For those participating during the three hours, there will be more Traces on the map, including an increase in Hogwarts School Traces and a free store pack with 50 Spell Energy and a Baruffio Brain Elixir from the Diagon Alley shop. Consuming the elixir during the event will triple the amount of Wizard XP. Dark Detectors will also last twice as long when placed at an inn throughout the community day.
Wizards Unite players in other regions can see what time the event starts for them at the community day blog post.