This is a new feature introduced in the 7th generation of Pokemon. In the games Pokemon Moon and Pokemon Sun, players who connect to the internet will get messages about a global event that is currently happening.
What I think of this feature is it’s a little strange. I don’t tend to pay too much attention to it, though I should. Tomorrow is the last day for the current one which happens to have something to do with people collecting as many battle points from the battle tree as possible. From the looks of it, the goal was met about 52 times. 2/4 of the events ever held were met, the first two hadn’t been met in the past.
I just don’t really see the point in the events, though they do give players rewards for achieving things at the end of the periods. I guess I’m just missing out on something. :>