Equinox

The Equinox was a unique event in Pokémon GO that began on September 22, 2017. This event celebrated the around the world.

Background
This event took place from September, 2017 through October , 2017.

To celebrate autumn in the Northern Hemisphere and spring in the Southern Hemisphere, Trainers were rewarded with double Stardust for Catching Pokémon and hatching Eggs.

Special 2 km Eggs were also available from spinning the Photo Disc at PokéStops. These Eggs had an increased chance of hatching Pokémon such as Chansey, Mareep, and Larvitar.

Special boxes were also available from the in-game Shop and featured items such as Lucky Eggs, Lure Modules, and Super Incubators which hatch Eggs 150% faster.

Finally, registering a new Pokémon to the Pokédex during this limited-time celebration awarded triple XP.

Pokémon Eggs hatchlings
Only these Pokémon were hatching from eggs during the event. After this time the all hatchlings were the same as prior the event.

Trivia

 * The event was extended by 24-hours, following a login issue on September 26, 2017.
 * The event ended at exactly 1:00pm PDT.