In the following list, most important dates with events - both in-game or IRL (related to Cities XL) - are listed:
- 2009-10-22: A Trial Version will be available.
- 2009-10-13: Starting tomorrow, Wednesday October the 14th, a weekly maintenance will be performed on the game and web servers every Wednesday morning from 9:30am to 12:00am Paris time (3:30pm to 6am New York time). During this maintenance, game servers, authentication servers and some parts of the website will be unavailable.
- 2009-10-12: A new planet has been added: Hyperion for the United Kingdon.
- 2009-10-10: Since you are numerous joining and some of you are already creating more than 1 city, we decided to open 3 new planets for the US, France and German players to populate: Janus for Germany, Pandora for France and Pollux for the United States.
- 2009-10-09: Launch of Cities XL in other countries.
- 2009-10-08: Launch of Cities XL in France and Germany.