Achievement Calendar is a free Chrome add-on developed by Alex Marshall. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This handy tool provides reminders for date-specific Xbox 360 and Xbox One achievements.

With Achievement Calendar, every time you open a new tab, you'll be greeted with a display of achievements that can only be unlocked on that specific day. Whether you're an avid gamer or just looking to maximize your gaming experience, this add-on is a must-have. It covers a wide range of games including popular titles like Halo: Master Chief Collection, Batman Arkham City, Dance Central 3, and many more.

Achievement Calendar is a convenient way to stay on top of time-limited achievements, ensuring you never miss out on unlocking those special in-game rewards. If you're an Xbox gamer, this add-on is a valuable tool to enhance your gaming experience.