Niantic has made an annoucement regarding celebration of the upcoming Autumnal (Northern Hemisphere) and Vernal (Southern Hemisphere) equinoxes in Pokémon GO!
During the event period, trainers will be able to earn more Stardust for catching Pokémon and hatching Eggs while walking around. PokéStops and Gyms will also have a special collection of 2 km Eggs with an opportunity to hatch Chansey, Mareep, Larvitar, and more. There will also be special boxes in the in-game shop featuring items such as Lucky Eggs, Lure Modules, and a new item known as Super Incubators, which will allow for Eggs to hatch 1.5 times quicker.
Additionally, registration of a new Pokémon to your Pokédex during the event will earn you three times the normal amount of XP.
The event runs from 1:00 p.m. PDT on September 22nd through 1:00 p.m. PDT on October 2nd.