I wont be able to get pokebank now Btw it came out 4 hours from this post :P
It ends on the 30th of September 2014.
"This Celebi was available to players who accessed Pokémon Bank from December 25, 2013 to September 30, 2014."
Source: http://bulbapedia.bulbagarden.net/wiki/List_of_game-based_Pokémon_distributions_in_Generation_VI
"If the player accesses Pokémon Bank before September 30, 2014, they can receive a special event Celebi. This particular Celebi knows Hold Back, an event-exclusive move similar to False Swipe."
Source: http://bulbapedia.bulbagarden.net/wiki/Pokémon_Bank
Hope I helped :)
September 30th, 2014, just like before it crashed. And the article talks about Europe, but it applies everywhere.
Source: http://www.nowgamer.com/news/2266392/pokemon_x_y_pokemon_bank_now_live_in_europe.html
It Began in December with those who have pokebank it will end September 30 of 2014 to learn how to get your Celebi watch this:https://www.youtube.com/watch?v=V7WBorGUrWY
