Raikou Day is the latest of a series of Pokémon Go Raid event days, with legendary birds, Articuno, Zapdos and Moltres in 2018 and since then the likes of Gengar and Lapras.
It's a great chance to get your hands on Raikou - one of the game's best electric types - as well as a possible shiny variant.
Here's everything we know about Raikou Day, including the Raikou Day start time, and below that info on other similar events gone by.
Raikou Day start day, start time and length
Raikou Day will take place on Saturday, June 29th, and will have a start time of 4pm to 7pm local time, giving you ample opportunity to catch as many Raikou as possible.
How does Raikou Day work?
All Gyms will have Raikou Raids spawn for the duration of the event, and you are free to Raid as many as you can fit into the time.
To help, there are five free Raid Passes on offer. After that, you have to use Premium Raid Passes to continue to participate..
Though - at the time of writing at least - there are no exclusive moves as part of the Raikou Day, there's a (rare) chance Shiny Raikou will make an appearance - estimated at about one in twenty if previous event days are anything to go by.
Here's how Shiny Raikou looks (thanks to iemandiets on reddit):
Once this is out the way, that's not the end - more completed Global Challenge rewards will see fellow legendary beasts Entei and Suicune have their own Raid Days later in the summer.
Their dates have yet to be announced, but expect them after their respective events.
A few new exciting additions are coming to the game - Armored Mewtwo, an on-going series of Pokémon Go Global Challenges, the tease of Shadow Pokémon and the Invasion of Team Go Rocket. In the meantime, we have a new Go Fest Global research task rewards and the Jump-Start Research quest and Field Research, which can help with some of the harder-to-find Gen 4 Pokémon. Elsewhere, you can read up on the latest the currently available Legendary Pokémon.