A time clock, sometimes known as a clock car machine or punch clock, is a mechanical (or electronic) timepiece used to assist in tracking the hours an employee of a company worked. In regards to mechanical time clocks this was accomplished by inserting a heavy paper card, called a time card, into a slot on the time clock. When the time card hit a contact at the rear of the slot, the machine would print day and time information on the card. This allowed a timekeeper to have an official record of the hours an employee worked to calculate and pay an employee.