What is the origin of the idiom "on the clock" and when to use it?

The origin of the idiom "on the clock" can be traced back to the early 20th century and is related to the practice of tracking time worked by employees. In industrial settings, employees would often punch a timecard or clock in and out to record their hours of work. It is commonly used in workplaces to refer to employees who are in their designated working hours and expected to perform their job duties.

What is the origin of the idiom "on the clock" and when to use it?

The idiom "on the clock" likely originated from the practice of measuring the distance a vehicle has traveled using an odometer, where the mileage is displayed on the vehicle's dashboard like a clock. This expression is used to indicate the distance a vehicle has traveled, often measured in miles or kilometers. It is a casual and straightforward way to discuss a vehicle's mileage.