Pokemon Bank is released on Christmas Day in Japan and Korea, and on December 27 elsewhere. The official X and Y website has the details on the trial period:
>If you download and open Pokémon Bank by January 31, 2014, you will be able to obtain a pass that will allow you to use the software for no charge for 30 days.
>Before February 1, 2014, you will need to:
>1. Download Pokémon Bank from the Nintendo eShop.
2. Open Pokémon Bank.
3. Follow the on-screen instructions to obtain your pass.
>This pass unlocks a 30-day trial period. During this time, you will be able to use all of the features in both Pokémon Bank and Poké Transporter without charge.
>If you download Pokémon Bank but do not open the software and obtain your pass by the end of January 31, 2014 (Friday), you will not be able to obtain the pass. Please be sure to take advantage of this opportunity while it lasts.