What is "clock off"

Usage examples of "clock off".

When Justin Gilead did not show up by eleven to make his first move, the referee would turn the clock off and award the game to Zharkov by default.

Then I would pack up everything very neatly, drop it in my pack, and hike again till it was time to clock off and go home.

Pitt threw a telephone, followed by a vase, followed by a clock off the mantel.