Pokémon Shuffle Version 1.1.10 is available for players of the game and the patch adds the
Pokémon Wild Safari. In the Pokémon Safari, players randomly encounter a Pokémon but they don't know which one until the Pokémon Safari begins. Some of these Pokémon are harder to meet than others and players need to attempt to encounter all the Pokémon before the Pokémon Safari disappears! There is no "Optimize" option in Pokémon Safari, so players need to choose the most powerful Pokémon for the encounter.
The Pokémon Wild Safari will be available from April 20th, 2015 at 06:00 UTC until May 2, 2015 at 06:00 UTC.
Details of this event have been added to our Pokémon Wild Safari page.
Sources:
http://www.pokemonshuffle.com/en-us/connectivity#daily and
http://www.pokemon.co.jp/ex/poketoru/news/post.php/31/