Niantic has announced that Uxie, Mesprit, and Azelf will be available to challenge in raids from Thursday, May 2nd, 2019 at 1 p.m. until Monday, May 27th, 2019, at 1 p.m. PDT (GMT −7).

Uxie, Mesprit, and Azelf surface in regional raids

Trainers, We received numerous reports from all over the world of Uxie, Mesprit, and Azelf. Your work uncovering the mystery of these Legendary Pokémon from the Sinnoh region has led to an amazing discovery! Professor Willow has verified that Uxie, Mesprit, and Azelf have appeared in different regions of the world and will be available to challenge in raids!

Date + Time

• Thursday, May 2, 2019, at 1 p.m. to Monday, May 27, 2019, at 1 p.m. PDT (GMT −7)

Features

• Asia-Pacific: Uxie will be available to challenge in raids
• Europe, the Middle East, Africa, and India: Mesprit will be available to challenge in raids
• The Americas and Greenland: Azelf will be available to challenge in raids
• If you’re extraordinarily lucky, you may encounter these extremely rare Legendary Pokémon in the wild in their different regions, even after the event!

Thank you for your work in helping to identify these Legendary Pokémon newly discovered in Pokémon GO. Keep exploring, Trainers!

Source: https://pokemongolive.com/en/post/regionalraids2019/