The app is structured like a quiz game. There are two versions:
1. Speedrun: You must find as many days as possible until your time runs out. There is a high score to keep track of your performance. Also, for each run, you can detect your percentage.
2. Practice: You can casually open the app and start finding days that the given random date corresponds to.
-- The app is highly customizable. It not only automatically stores your past mistakes so that you can improve yourself but you can also customize how you want the date given to you. There are various formats to choose from. --