Clocks are used to limit the length of a game.
You have 60 seconds to complete your turn.
Each player gets 15 minutes thinking time for the entire game. The time left is shown next to their names.
Another clock is used to count the time that each player separately takes for making his own moves. You have 60 seconds to complete your turn.
If you run out of time, you lose the game, and thus must budget your time.