In the United States, shift work is defined as any regular work schedule that falls outside the standard work day of 9am to 5pm. Shift work includes swing shifts, which begin the afternoon and end around midnight; and night or graveyard shifts, which begin in the late evening and end in the early morning. The term may also be applied to continuous shifts that span up to 40 consecutive hours at a time; these schedules are common in industries that require round-the- clock coverage, such as healthcare and firefighting.
Most shift workers follow the same schedule on a day-to-day basis. This is known as a “same shift pattern.” Other workers may work an early shift one day, and then a night shift the next; this is known as a multiple shift pattern.
Shift work is found in virtually every industry, but most commonly in fields like healthcare and medicine, law enforcement and security, firefighting, transportation, food service, hospitality and the military.