When will the new Season of Pokémon Ultra Sun and Ultra Moon release?

The Pokémon Company International (PCS) announced the first official information regarding the Pokémon Ultra Summer and Ultra Sun Ultra Moon expansion on Saturday.
Players who purchased Pokémon Ultra Spring and Ultra Summer will receive an update on April 18, 2018, in which the Pokémon Company will update the game to include a brand new season, Pokémon Ultra Moon.
Pokémon Ultra Night will be available on April 22.
The Pokémon Company also announced the Pokémon League Champions Spring and Summer 2017 and Spring and Spring 2018, the Pokémon Super Summer 2018 and Pokémon Super Fall 2018, and the Pokémon Festival of the Americas 2018.
All three Pokémon Super Festivals will be held in North America.
For the third time in the series, Pokémon Sun and Moon will also launch in the United States in 2018.