Board Thread:Plants vs. Zombies 2: It's About Time/@comment-5792287-20131203091220/@comment-24158944-20131211010054

PnFforever

the far future is still not unlocked. which you could find out by reading this thread.

Awesomesix

He already said  that if you already beat the level 8's, you start with 1 key for the eventual release of far future.