dutyhour

Duty hour refers to the period during which an employee is required to be at work or available to perform tasks for an employer. It encompasses time spent actively performing duties as well as on-call or standby periods when the worker must be reachable and ready to work. Duty hours are used in regulations and contracts to define expected working time and to distinguish them from breaks, rest periods, and overtime pay.

Regulations vary by country and industry. In healthcare residencies in the United States, duty-hour rules limit fatigue and protect safety. The ACGME typically restricts residents to about 80 work hours per week, averaged over four weeks; in-hospital duty periods commonly cap at 24 hours, with a transitional window, and residents should have at least one day free of duty per week on average. Rest between shifts and limits on consecutive nights are also specified.

Elsewhere, duty hours are governed by labor laws and sector regulations. In aviation, crew have strict duty-and-rest rules to maintain alertness. In many industries, on-call time counts as duty hours if the worker must be available; whether it is compensable or included in the total depends on jurisdiction and contract. Some places count all on-call time toward the cap, others only restricted periods.

Understanding duty hours supports fatigue management, safety, and compliance with labor standards, and interacts with overtime, breaks, and time off in policies and agreements.