You have to wait for 120 days (4 months) to play again.
Also some hints: In order to get the +5 stat cap reward on your characters (which requires 3 months of activation, yet all EJ accounts always stay -1 month age), the time of your EJ account creation is factored in. So create an account now, wait 2 months, then pay for 1 month, and at the end you will have the +5 stat cap reward. Another thing you should do is create 6 characters on your main shard while you subscribe for the 1 month. EJ only allows you to create 2 characters per shard, however, if you already have more than 2 characters, you can later keep them when you go EJ.
Good luck!