Definition of "clock on" []

• Register one's arrival at work (verb)

WordNet. Princeton University. 2010.

• "She watched it for a full minute, the second hands still ticking together perfectly, when all of a sudden, it was as if the clock on the right hiccuped: The minute hand jumped backward instead of forward!"
• "Suddenly her wild pacing brought her before the clock on the chimney-piece."
• "The clock on the Jumbotron scoreboard read 9:23 p.m. when Derek Jeter took two fastballs from Tillman."