time clock

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A clock that records the starting and quitting times of employees, usually by punching timecards.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A device that records, on timecards, the times that employees start and finish work.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun clock used to record the hours that people work