In short: A clock with two clock faces, one for each player. When one runs, the other stands still.
A chess clock is two clocks joined together: when one runs, the other stands still. When you have made your move you press the clock. Your time stops and your opponent's starts. Only once you have pressed the clock is the move complete.
The rules at the clock
- Same hand. Press the clock with the same hand you made the move with.
- No hovering. It is forbidden to keep your finger on the clock or to hover over it.
- Handle it with care. You may not press it forcibly, pick it up or knock it over, and you may not press it before you have moved.
- Adjust on your own time. Only the player whose clock is running may adjust the pieces.
Pressing the clock without making a move is penalized as an illegal move.
Analog and digital
An analog chess clock has two clock faces side by side and a button on each side. When the time is up, a little flag falls. A digital clock shows the time on two displays and can add a few seconds after every move. That is called an increment; read more under time control.
A little history
Chess clocks were first used in a tournament in London in 1883. Today they are used in every tournament except in correspondence chess, where the time is counted in days. The clock has also been taken up by other two-player games, such as go and shogi.
Thinking of buying a chess clock? We go through what to look for in the shopping guide.
Frequently asked questions
Which hand do you press the clock with?
The same hand you made the move with. It is also forbidden to keep your finger on the clock or to hover over it.
When did chess clocks come into use?
They were first used in a tournament in London in 1883. Today they are used in every tournament except in correspondence chess.
Updated November 14, 2026