To calculate work hours, an employer records the time the employee arrives at a prescribed workplace, or on duty, and subtracts it from the time the employee stops working on that particular day. The U.S. Department of Labor describes work hours as the time when an employee arrives to work.
The recorded time must conform to the policies of that particular organization. For example, if the policy states that the employer should round off the working hours to the next quarter hour, the total working hours of an employee who has worked for five hours and seven minutes are five hours and 15 minutes, or 5.25 hours in decimal form.
If the employee works for different rates at different shifts, the employer divides the working hours according to the shifts and their rates. For instance, if an employee works as a cook in the morning and a waiter in the afternoon at the same restaurant, the employer divides the work hours into two shifts and their rates.
Employees must calculate the work hours of a particular employee on a weekly basis even if the pay day takes longer than a week. If the required work hours in a week are in excess of 40 hours, the employer pays the employee 1.5 times the regular pay rate, according to the Fair Labor Standards Act.