A chess clock consists of two connected clocks which can't run at the same time.
Use it as a game clock to measure the time used by two players for
their moves e.g. in game of chess. Stopping one clock will start the
other one. The purpose is to keep track of the total time each player
takes for his or her own moves, and ensure that neither player overly
delays the game.
Features:
choose the same time for both players or individually