time clock 
noun
1A clock with a device for recording employees' times of arrival and departure: employees have to punch a time clock...
- And he believes when he punches the time clock and goes home, the public should mind its own business.
- But at the same time, very few players seem to understand that they win money just like a worker punching a time clock.
- The absolute worst work condition we ever heard about was a 1960's factory where the owner made all workers punch out on the time clock to use the bathroom.
2A switch mechanism activated at preset times by a built-in clock: you can save energy by fitting a time clock to your boiler...
- Regeneration is usually started by a preset time clock; some units are started by water-use meters or hardness detectors.
- Some systems use a large-capacity pump operated by a time clock to supply flush water instead of a flush tank.