Shift work
Encyclopedia
Shift work is an employment
Employment
Employment is a contract between two parties, one being the employer and the other being the employee. An employee may be defined as:- Employee :...

 practice designed to make use of the 24 hours of the clock. The term "shift work" includes both long-term night shifts and work schedules in which employees change or rotate shifts.

A related yet different concept, the work shift, is the time period during which a person is at work.

Health consequences

The February 15, 2005 issue of American Family Physician
American Family Physician
American Family Physician is a semimonthly, peer-reviewed medical journal of the American Academy of Family Physicians. AFP’s chief objective is to provide high-quality continuing medical education for more than 190,000 family physicians and other primary care clinicians...

 noted that shift work has been associated with cluster headache
Cluster headache
Cluster headache, nicknamed "suicide headache", is a neurological disease that involves, as its most prominent feature, an immense degree of pain in the head. Cluster headaches occur periodically: spontaneous remissions interrupt active periods of pain. The cause of the disease is currently unknown...

s. Health problems in the short term can also include fatigue, stress and loss of concentration, a higher rate of absence from the job and poor sexual performance, as shown in the majority of 200 variable-shift workers in a recent study in Kuwait.

Long term consequences of disturbing natural circadian rhythm
Circadian rhythm
A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

s have been investigated also. A study by Knutsson et al. in 1986 found that shift workers who had worked in that method for 15 years or more were 300% more likely to develop ischemic heart disease.

In 1978 Cohen et al. proposed that reduced production of the hormone melatonin might increase the risk of breast cancer, citing "environmental lighting" as a possible causal factor. Working the night shift first became associated with higher rates of cancer in 1987. This may be due to alterations in circadian rhythm: melatonin, a known tumor suppressant, is generally produced at night and late shifts may disrupt its production. Multiple studies have documented a link between night shift work and the increased incidence of breast cancer.

The WHO's International Agency for Research on Cancer
International Agency for Research on Cancer
The International Agency for Research on Cancer is an intergovernmental agency forming part of the World Health Organisation of the United Nations....

 listed "shiftwork that involves circadian disruption" as a probable carcinogen in 2007 (IARC Press release No. 180).

UCSF neurologist Louis Ptacek, who studies circadian rhythm
Circadian rhythm
A circadian rhythm, popularly referred to as body clock, is an endogenously driven , roughly 24-hour cycle in biochemical, physiological, or behavioural processes. Circadian rhythms have been widely observed in plants, animals, fungi and cyanobacteria...

s, genes and sleep behaviors, has been quoted: "It's not surprising, we have evolved on a planet that is rotating every 24 hours. Our internal clock is more than just when we sleep and wake. It's related to cell division and it regulates our immune systems. When we battle our internal clock, that has complications."

A good review of current knowledge of the health consequences of exposure to artificial light at night and an explanation of the causal mechanisms was published in the Journal of Pineal Research in 2007.

One study suggests that, for those working a night shift (such as 23:00 to 07:00), it may be advantageous to sleep in the evening (14:00 to 22:00) rather than the morning (08:00 to 16:00). The study's evening sleep subjects had 37% fewer episodes of attentional impairment than the morning sleepers.

The health consequences of shift work may depend on whether one is a day person
Lark (person)
Lark is a term used to describe a person who usually gets up early in the morning and goes to bed early in the evening. Other terms are "morning person" and "early bird"....

 or a night person
Night owl (person)
Night owl is a term used to describe a person who tends to stay up until late at night. Another name for a night owl is evening person.The opposite of a night owl is an early bird, a lark as opposed to owl, someone who tends to begin sleeping at a time that is considered early and also wakes early...

 and what shift one is assigned to.

Shift work management practices

The practices and policies put in place by managers of round-the-clock or 24/7 operations can significantly influence shift worker alertness (and hence safety) and performance.

Air traffic controller
Air traffic controller
Air traffic controllers are the people who expedite and maintain a safe and orderly flow of air traffic in the global air traffic control system. The position of the air traffic controller is one that requires highly specialized skills...

s typically work an 8-hour day, 5 days per week. Research has shown that when controllers remain "in position" for more than two hours, even at low traffic levels, performance can deteriorate rapidly, so they are typically placed "in position" for 30-minute intervals (with 30 minutes between intervals).

These practices and policies can be fairly obvious: selecting an appropriate shift schedule or rota
Schedule (workplace)
A schedule, often called a rota, is a list of employees who are working on any given day, week, or month in a workplace. A schedule is necessary for the day-to-day operation of any retail store or manufacturing facility. The process of creating a schedule is called scheduling...

 and using an employee scheduling software
Employee scheduling software
Employee scheduling software automates the process of creating and maintaining a schedule. Such software will usually track vacation time, sick time, compensation time, and alert when there are conflicts. As a database of schedules are accumulated over time, it may analyze past activity and...

 to maintain it, setting the length of shifts, managing overtime, increasing lighting levels, or providing shift worker lifestyle training to help shift workers better handle issues such as understanding basic circadian physiology, sleep and napping, caffeine usage, social life issues, diet and nutrition, etc. They may also be more indirect: retirement compensation based on salary in the last few years of employment (which can encourage excessive overtime among older workers who may be less able to obtain adequate sleep), or screening and hiring of new shift workers that assesses adaptability to a shift work schedule.

A day may be divided into three shifts, each of 8 hours, and each employee works just one of those shifts; they might, for example, be midnight to 08:00, 08:00 to 16:00, 16:00 to midnight. Generally, "first shift" refers to the day shift, with "second shift" running from late afternoon to midnight or so, and "third shift" being the night shift. On occasion, more complex schedules are used, sometimes involving employees changing shifts, in order to operate during weekends
Workweek
The workweek and weekend are those complementary parts of the week devoted to labour and rest respectively. The legal working week , or workweek , is the part of the seven-day week devoted to labor. In most Western countries it is Monday to Friday. The weekend comprises the two traditionally...

 as well, in which case there will be four or more sets of employees.

12-hour work shifts are also in use. In a modern steelworks, four sets of personnel are used, working consecutive days in one 12-hour shift (06:00 – 18:00 and vice-versa). Shift A will work days, and shift B nights, over a 48-hour period, before handing over to shifts C and D and taking 48 hours off. In the offshore petroleum industry, employees may work 14 consecutive days or nights, 06:00 – 18:00 or 18:00 – 06:00, followed by three or four weeks free. The svingskift (literally: "swing shift") in the offshore petroleum industry in Norway refers to a two-week tour during which employees work 12-hour days the first seven days and 12-hour nights the second (or vice versa).

Shift work was once characteristic primarily of the manufacturing industry, where it has a clear effect of increasing the use that can be made of capital equipment and allows for up to three times the production compared to just a day shift. It contrasts with the use of overtime
Overtime
Overtime is the amount of time someone works beyond normal working hours. Normal hours may be determined in several ways:*by custom ,*by practices of a given trade or profession,*by legislation,...

 to increase production at the margin. Both approaches incur higher wage costs. Although 2nd-shift worker efficiency levels are typically 3–5% below 1st shift, and 3rd shift 4–6% below 2nd shift, the productivity level, i.e. cost per employee, is often 25% to 40% lower on 2nd and 3rd shifts due to fixed costs which are "paid" by the first shift.

In general, requiring workers to live on a time-shifted schedule for extended periods is unpopular, and this typically must be paid for at a premium. It is common in heavy industry, particularly automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

 and textile
Textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...

 manufacturing and is becoming more common in locations where a shut-down of equipment would incur an extensive restart process. Food manufacturing plants, in particular, have extensive cleaning programs
Hazard Analysis and Critical Control Points
Hazard analysis and critical control points, or HACCP , is a systematic preventive approach to food safety and pharmaceutical safety that addresses physical, chemical, and biological hazards as a means of prevention rather than finished product inspection...

 that are required before any restart. The use of shift work in manufacturing varies greatly from country to country. Shift work is common in the transportation sector as well. Some of the earliest instances appeared with the railroads, where freight trains have clear (i.e. passenger-free) tracks to run on at night. Shift work has been traditional in law enforcement and the armed forces: for example sailor
Sailor
A sailor, mariner, or seaman is a person who navigates water-borne vessels or assists in their operation, maintenance, or service. The term can apply to professional mariners, military personnel, and recreational sailors as well as a plethora of other uses...

s must be available to handle a vessel around the clock, and a system of naval watches organized to ensure enough hands are on duty at any time. This is shift work by another name.

Service industries now increasingly operate on some shift system; for example a restaurant or convenience store
Convenience store
A convenience store, corner store, corner shop, commonly called a bodega in Spanish-speaking areas of the United States, is a small store or shop in a built up area that stocks a range of everyday items such as groceries, toiletries, alcoholic and soft drinks, and may also offer money order and...

 will normally each day be open for much longer than a working day. Shift work is also the norm in governmental and private employment in fields related to public safety and healthcare, such as Emergency Medical Services
Emergency medical services
Emergency medical services are a type of emergency service dedicated to providing out-of-hospital acute medical care and/or transport to definitive care, to patients with illnesses and injuries which the patient, or the medical practitioner, believes constitutes a medical emergency...

, police, fire prevention, security and hospital
Hospital
A hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....

s. Companies working in the field of meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

, such as the National Weather Service
National Weather Service
The National Weather Service , once known as the Weather Bureau, is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration of the United States government...

 and private forecasting companies, also utilize shift work, as constant monitoring of the weather is necessary.

Much of the Internet services and Telecommunication
Telecommunication
Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded...

 industry relies on shift work to maintain worldwide operations and uptime
Uptime
Uptime is a measure of the time a machine has been up without any downtime.It is often used as a measure of computer operating system reliability or stability, in that this time represents the time a computer can be left unattended without crashing, or needing to be rebooted for administrative or...

.

6 on 6 off

Consists of 3 days and 3 nights.Then 6 days off. These will alternate between other crews A.K.A teams for a full 24/7 operation.

Three-shift system

The "three-shift system" is the most common pattern, with "first" from 06:00 to 14:00, "second" from 14:00 to 22:00, and a "third" (or "night") shift from 22:00 to 06:00 This is generally worked over a five-day week; to provide coverage 24/7, employees have their days off ("weekends") on different days.

All of the shifts have desirable and less desirable qualities. First shift has very early starts, so time in the evening before is heavily cut short. The second shift (or "swing shift") occupies the times during which many people finish work and socialize. The third shift creates a situation in which the employee must sleep during the day.

Generally, employees stay with the same shift for a period of time, as opposed to cycling through them; this is seen as healthier.

Three-shift example:
Time Sat Sun Mon Tues Wed Thur Fri
06:00–14:00 Shift 1 Shift 1 Shift 1 Shift 1 Shift 1 Off Off
14:00–22:00 Shift 2 Shift 2 Shift 2 Shift 2 Shift 2 Off Off
22:00–06:00 Shift 3 Shift 3 Shift 3 Shift 3 Shift 3 Off Off

Four on, four off

Four on, four off is a shift pattern that is being heavily adopted in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 and in some parts of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. An employee works for four days, usually in 12-hour shifts (7:00 to 7:00) then has four days off. While this creates a "48-hour week"(42-hour average over the year) with long shifts, it may be preferred because it shrinks the work week down to four days, and then gives the employee four days rest—double the time of a usual weekend. Due to the pattern, employees effectively work an eight-day week, and the days they work vary by "week". As with three-shift system, most employees stay with the same shift rather than cycling through them.

Four on, four off example:
Time 7:00-7:00 Sat Sun Mon Tues Wed Thur Fri Sat
07:00–19:00 Day 1 Day 2 Day 3 Day 4 Off Off Off Off

Navy Three-shift underway system

The US Navy uses a three shift system that relies on an 18 hour day instead of a 24 hour day. The 24 hour period is broken up into 4 shifts. 00-06, 06-12, 12-18, and 18-00. A sailor will stand watch on his shift. During his offgoing shift he will have time to perform maintenance, work on qualifications and handle all his collateral duties. During the oncoming time the sailor has time to sleep, relax, and do whatever personal things he needs to do like laundry.

Navy Three-shift example: Shift 1
Time Sat Sun Mon Tues Wed Thur Fri
00:00–06:00 Shift 1 Offgoing Oncoming Shift 1 Offgoing Oncoming Shift 1
06:00–12:00 Offgoing Oncoming Shift 1 Offgoing Oncoming Shift 1 Offgoing
12:00–18:00 Oncoming Shift 1 Offgoing Oncoming Shift 1 Offgoing Oncoming
18:00–00:00 Shift 1 Offgoing Oncoming Shift 1 Offgoing Oncoming Shift 1

Navy Three-shift example: Shift 2
Time Sat Sun Mon Tues Wed Thur Fri
00:00–06:00 Oncoming Shift 2 Offgoing Oncoming Shift 2 Offgoing Oncoming
06:00–12:00 Shift 2 Offgoing Oncoming Shift 2 Offgoing Oncoming Shift 2
12:00–18:00 Offgoing Oncoming Shift 2 Offgoing Oncoming Shift 2 Offgoing
18:00–00:00 Oncoming Shift 2 Offgoing Oncoming Shift 2 Offgoing Oncoming

Navy Three-shift example: Shift 3
Time Sat Sun Mon Tues Wed Thur Fri
00:00–06:00 Offgoing Oncoming Shift 3 Offgoing Oncoming Shift 3 Offgoing
06:00–12:00 Oncoming Shift 3 Offgoing Oncoming Shift 3 Offgoing Oncoming
12:00–18:00 Shift 3 Offgoing Oncoming Shift 3 Offgoing Oncoming Shift 3
18:00–00:00 Offgoing oncoming Shift 3 Offgoing Oncoming Shift 3 Offgoing

Four on, three off

Each employee works four days and gets a three-day weekend. For some types of manufacturing, this is a win-win arrangement. For example, Kyanize Paint Company had been making 3 batches of paint per day, Monday through Friday (3 × 5 = 15). They changed to making 4 batches of paint, Monday through Thursday (4 × 4 = 16). Total worker hours remained the same, but profits increased. In exchange for two additional hours of work per day, over 4 days, workers got an additional day off every week (see also the book, 4 Days, 40 Hours
4 Days, 40 Hours
4 Days, 40 Hours is a book by Riva Poor reporting on a "revolution in work and leisure" from the rearranged work week. In some cases, the book shows, companies can increase production and profit while giving employees more time off. For example, Kyanize Paints would make 3 batches of paint on each...

).

Four on, two off

In four on, two off the employee only gets two days off. In a seven-day period, this adds up to 60 hours worked (on average, based on 12-hour shifts). Four on, two off is mainly adopted by industries in which employees do not engage in much physical activity.

Four on, two off example:
Time Sat Sun Mon Tues Wed Thur Fri
07:00 to 19:00 Day 1 Day 2 Day 3 Day 4 Off Off Day 5

Four on, one off

In four on, one off the employee only gets one day off. In a seven-day period, this adds up to 48 hours worked (on average, based on 8-hour shifts). Four on, one off is mainly adopted by industries in which companies prefers to work for all days of the week with four shifts and where laws do not let employees work for 12 hours a day for several days.

Four on, one off example:
Time Sat Sun Mon Tues Wed Thur Fri
07:00–15:00 Day 1 Day 2 Day 3 Day 4 Off Day 5 Day 6

Two days, two nights, four off

A variation is the two days, two nights, four off pattern of working. In this shift schedule, employees work 12-hour shifts from 06:00 to 18:00 on day shifts and from 18:00 to 06:00 on nights. This pattern is currently in use by HM Coastguard in the UK, and employs four separate teams to maintain 24/7 coverage.

Two days, two nights, four off example:
Time Sat Sun Mon Tues Wed Thur Fri Sat
06:00–18:00 Day 1 Day 2 Off Off Off Off Off Off
18:00–06:00 Off Off Day 3 Day 4 Off Off Off Off

5/4/9s

"5/4/9s" (or "Five/Four Nines", or "9/80") is another variation. Employees work in 2 week cycles. Week 1 the employee works 4 days of 9 hours followed by 1 day of 8 hours with 2 days off (week 1: 44 hours). Week 2 the employee works 4 days of 9 hours with 3 days off (week 2: 36 hours). This pattern works to 80-hours in a 2 week pay-period (comparable to working 8 hours a day for 5 days a week). The benefit to working an extra hour a day gives you a "normal" 2 day weekend followed by a long 3 day weekend the next. Typical working hours for this type of shift would be 06:00 to 15:30 (9 hours with 30 minutes lunch) and 06:00 to 14:30 (8 hours with 30 minutes lunch) on the 8-hour work day. Often the employer will alter the starting times (e.g., start at 07:00 or 08:00). Also referred to as "9/80" as employees have nine days to work 80 hours.

5/4/9s shift example:
Week Mon Tues Wed Thur Fri Sat Sun
Week 1 9 hrs 9 hrs 9 hrs 9 hrs 8 hrs Off Off
Week 2 9 hrs 9 hrs 9 hrs 9 hrs Off Off Off

12/24/12/48

12/24/12/48 (or 12/24) is another variation. Employees work in shifts of 12 hours; first a daily shift (e.g., 07:00 to 19:00), followed by 24 hours rest, then a nightly shift (19:00 to 07:00), finishing with 48 hours rest. This pattern needs four teams for full coverage, and makes an average 42-hour workweek.

12/24/12/48 shift example:
Time Sat Sun Mon Tues Wed Thur Fri
06:00–18:00 Day 1 Off Off Off Day 3 Off Off
18:00 to 06:00 Off Day 2 Off Off Off Day 4 Off

Continental shift

Continental shift, adopted primarily in central Europe, is a rapidly changing three-shift system that is usually worked for seven days straight, after which employees are given time off. For example, three mornings, two afternoons, and then two nights.

Continental shift example:
Time Sat Sun Mon Tues Wed Thur Fri
06:00–14:00 Shift 1 Shift 1 Shift 1 Off Off Off Off
14:00 to 22:00 Off Off Off Shift 1 Shift 1 Off Off
22:00–06:00 Off Off Off Off Off Shift 1 Shift 1

Split shift

Split shift is used primarily in the catering, transport, hotel, and hospitality industry. Waiters and chefs work for four hours in the morning (to serve lunch), then four hours in the evening (to serve an evening meal). The average working day of a chef on split shifts could be 10:00 to 14:00 and then 17:00 to 21:00

Split shift example:
Time Sat Sun Mon Tues Wed Thur Fri
10:00–14:00 On On On On On Off Off
14:00–17:00 Off Off Off Off Off Off Off
17:00–21:00 On On On On On Off Off

Earlies and lates

Earlies and lates is used primarily in industries such as customer service (help desk
Help desk
A help desk is an information and assistance resource that troubleshoots problems with computers or similar products. Corporations often provide help desk support to their customers via a toll-free number, website and e-mail. There are also in-house help desks geared toward providing the same kind...

/phone-support), convenience stores, child care (day nurseries), and other businesses that require coverage greater than the average 9:00 to 5:00 working day in the UK. Employees work in two shifts that largely overlap, such as early shift from 08:00 to 16:00 and late shift from 10:00 to 18:00

Earlies and lates shift example:
Time Sat Sun Mon Tues Wed Thur Fri
08:00–16:00 Shift 1 Shift 1 Shift 1 Shift 1 Shift 1 Off Off
15:00–23:00 Shift 2 Shift 2 Shift 2 Shift 2 Shift 2 Off Off

7-day fortnight shift

In the 7-day fortnight shift pattern, employees work their allotted hours within 7 days rather than 10. Therefore, 41 hours per week equate to 82 hours per fortnight
Fortnight
The fortnight is a unit of time equal to fourteen days, or two weeks. The word derives from the Old English fēowertyne niht, meaning "fourteen nights"....

 (fourteen days and nights), which is worked in seven days, at 11–12 hours per shift. This shift structure is used in the broadcast
Broadcast
Broadcast or Broadcasting may refer to:* Broadcasting, the transmission of audio and video signals* Broadcast, an individual television program or radio program* Broadcast , an English electronic music band...

 television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

 industry, as well as many law enforcement
Law enforcement agency
In North American English, a law enforcement agency is a government agency responsible for the enforcement of the laws.Outside North America, such organizations are called police services. In North America, some of these services are called police while others have other names In North American...

 agencies, as well as health care fields such as nursing and clinical laboratories in the US.

7-day fortnight shift example:
Week 1
Time Sat Sun Mon Tues Wed Thur Fri
Days
08:00 to 20:00
Shift 'A'
Day 1
Shift 'A'
Day 2
Shift 'C'
Day 1
Shift 'C'
Day 2
Shift 'C'
Day 3
Shift 'A'
Day 3
Shift 'A'
Day 4
Nights
20:00 to 08:00
Shift 'B'
Night 1
Shift 'B'
Night 2
Shift 'D'
Night 1
Shift 'D'
Night 2
Shift 'D'
Night 3
Shift 'B'
Night 3
Shift 'B'
Night 4

Week 2
Time Sat Sun Mon Tues Wed Thur Fri
Days
08:00 to 20:00
Shift 'C'
Day 4
Shift 'C'
Day 5
Shift 'A'
Day 5
Shift 'A'
Day 6
Shift 'A'
Day 7
Shift 'C'
Day 6
Shift 'C'
Day 7
Nights
20:00 to 08:00
Shift 'D'
Night 4
Shift 'D'
Night 5
Shift 'B'
Night 5
Shift 'B'
Night 6
Shift 'B'
Night 7
Shift 'D'
Night 6
Shift 'D'
Night 7


One of the advantages of using this pattern is each shift pair, for example A and B, will get time off on weekends alternatively, because the schedule is fixed and does not drift.

DuPont 12-Hour rotating shift

The DuPont 12-Hour rotating shift provides 24/7 coverage using 4 crews and 12-hour shifts while providing a week off. Average hours is 42 per week but contains a 72-hour week which can be challenging. It is used in several manufacturing industries in the US. Companies that have gone to this schedule have noticed a decrease in accidents plus more rest for employees, less call ins, and more coverage when crews are short handed. In all the schedule is designed to improve safety.

DuPont 12-Hour rotating shift example:
Week Fri Sat Sun Mon Tues Weds Thurs
1 Nights Nights Nights Nights Off Off Off
2 Days Days Days Off Nights Nights Nights
3 Off Off Off Days Days Days Days
4 Off Off Off Off Off Off Off

Five and two

The five and two provides 24/7 coverage using 4 crews and 12-hour shifts over a fortnight. Average hours is 42 per week but contains a 60-hour week which can be challenging.

Five and two shift example:
Week Fri Sat Sun Mon Tues Weds Thurs Fri Sat Sun Mon Tues Weds Thurs
1 Nights Nights Nights Off Off Nights Nights Off Off Off Days Days Off Off
2 Days Days Days Off Off Days Days Off Off Off Nights Nights Off Off
3 Off Off Off Swing Swing Off Off Swing Swing Swing Off Off Swing Swing
4 Off Off Off Days Days Off Off Days Days Days Off Off Days Days

Seven-day eight-hour rotating shift

The seven-day eight-hour rotating shift provided 24/7 coverage using 8-hour shifts with 14 crews. Consisted of a morning shift from 07:00 to 15:00, a swing shift from 15:00 to 22:30 and a night shift from 22:30 to 07:30 Each shift was worked for five days straight. The 8-hour shifts allowed vacations and absences to be covered by splitting shifts or working double shifts. The run of day shifts was 56 hours but the 8-hour shift provided time for some socializing after work. Was once common in the pulp and paper industry in the Western United States but has been largely replaced by a 8 days, 8 swing, 5 nights, 9 off, 8-hour rotation.

Seven-day eight-hour rotating shift example:
Week Sun Mon Tues Weds Thurs Fri Sat
1 Day Day Day Day Day Off Off
2 Swing Off Off Swing Swing Swing Swing
3 Night Night Off Off Night Night Night
4 Day Day Day Day Off Off Day
5 Swing Swing Swing Swing Swing Off Off
6 Off Night Night Night Night Night Off
7 Off Off Day Day Day Day Day
8 Swing Swing Swing Swing Swing Off Off
9 Night Off Off Night Night Night Night
10 Day Day Off Off Day Day Day
11 Swing Swing Swing Off Off Swing Swing
12 Night Night Night Night Off Off Night
13 Day Day Day Day Day Off Off
14 Off Swing Swing Swing Swing Swing Off
15 Off Off Night Night Night Night Night

Sixes

Submarine sailors in the American Navy engage in a pattern known as sixes while underway. Instead of a 24-hour day, the ship operates on an 18-hour schedule. Any given individual is scheduled to stand watch for 6 hours, perform any other duties and engage in leisure time for 6 hours, then sleep for 6 hours. If enough personnel are available, a given watchstation may benefit from a fourth man referred to as the midnight cowboy. He will stand the same 6-hour watch in a given 24-hour period, usually from midnight to 06:00 (hence the midnight portion of the name, which is most often shortened to just cowboy) and the person who would normally stand that watch is free. This gives rise to a schedule of six on, twelve off, six on, thirty off, six on, twelve off.

Firefighting schedules

In many departments, firefighters work 24-hour shifts. They are authorized to sleep in the fire station
Fire station
A fire station is a structure or other area set aside for storage of firefighting apparatus , personal protective equipment, fire hose, fire extinguishers, and other fire extinguishing equipment...

 at night but are still subject to calls for service the entire shift. Departments have many options for scheduling firefighters for coverage. One option is 24 on/48 off, where a firefighter will work 24 hours and have 48 hours off, regardless of the day of the week or the holidays. Often they will be scheduled in an A–B–C pattern. Thus, a firefighter will be assigned to A, B or C shift and work whenever that letter is on the calendar.
California roll shift schedule

Another option is known as a California roll, where some shifts will be close together but allow for several days off. One option is thus:
Time Sat Sun Mon Tues Wed Thur Fri
Week 1 07:00 to 07:00 A B A C A C B
Week 2 07:00 to 07:00 C B


where a firefighter will work 24 hours on, 24 off, 24 on, 24 off, 24 on, 96 hours (4 days) off.

Another way to do this is:
Time Sat Sun Mon Tues Wed Thur Fri
Week 1 07:00 to 07:00 A B A B C A C
Week 2 07:00 to 07:00 A B C B C


where a firefighter will work one day, off one, work one, off two, work one, off four days.
Four-platoon 24-hour shift schedule

Another variation of the 24-hr shift schedule is a 4-platoon system, averaging 42 hours/week. Thus, the schedule is 24 on, 48 off, 24 on, 96 off, on a 4-day rotation.
Week Mon Tues Wed Thur Fri Sat Sun
Week 1 A D B A C B D
Week 2 C A D B A C B
Week 3 D C A D B A C
Week 4 B D C A D B A

Alternate Four-platoon 24-hour shift schedule

Another variation of the 24-hr shift schedule is a 4-platoon system, averaging 48 hours per week for three weeks and 24 hours the fourth week. Thus, the schedule is 24 on, 72 off.
Week Mon Tues Wed Thur Fri Sat Sun
Week 1 A B C D A B C
Week 2 D A B C D A B
Week 3 C D A B C D A
Week 4 B C D A B C D

Graveyard shift

Graveyard shift, night shift or third shift (3rd shift) means a shift of work running through the early hours of the morning, especially shifts from midnight until 08:00 or from 23:00 until 07:00. There is no certainty as to the origin of this phrase; according to Michael Quinion
Michael Quinion
Michael Quinion is a British etymologist and writer. He runs the web site World Wide Words, devoted to linguistics. He graduated from Cambridge University, where he studied physical sciences after which he joined BBC radio as a studio manager.-Writer:...

 it is little more than "an evocative term for the night shift … when … your skin is clammy, there's sand behind your eyeballs, and the world is creepily silent, like the graveyard."

In 2007, the World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 (WHO) announced that working the graveyard shift would be listed as a "probable" cause of cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

.

Industries

Industries requiring 24/7 cover are those that employ workers on a shift basis, for example:
  • Casino
    Casino
    In modern English, a casino is a facility which houses and accommodates certain types of gambling activities. Casinos are most commonly built near or combined with hotels, restaurants, retail shopping, cruise ships or other tourist attractions...

  • Customer service
    Customer service
    Customer service is the provision of service to customers before, during and after a purchase.According to Turban et al. , “Customer service is a series of activities designed to enhance the level of customer satisfaction – that is, the feeling that a product or service has met the customer...

     including call centers
  • Death care (medical examiner
    Medical examiner
    A medical examiner is a medically qualified government officer whose duty is to investigate deaths and injuries that occur under unusual or suspicious circumstances, to perform post-mortem examinations, and in some jurisdictions to initiate inquests....

     or coroner
    Coroner
    A coroner is a government official who* Investigates human deaths* Determines cause of death* Issues death certificates* Maintains death records* Responds to deaths in mass disasters* Identifies unknown dead* Other functions depending on local laws...

    )
  • Emergency
    Emergency
    An emergency is a situation that poses an immediate risk to health, life, property or environment. Most emergencies require urgent intervention to prevent a worsening of the situation, although in some situations, mitigation may not be possible and agencies may only be able to offer palliative...

     response systems
    • Firefighting
      Firefighter
      Firefighters are rescuers extensively trained primarily to put out hazardous fires that threaten civilian populations and property, to rescue people from car incidents, collapsed and burning buildings and other such situations...

    • Paramedic services
      Emergency medical services
      Emergency medical services are a type of emergency service dedicated to providing out-of-hospital acute medical care and/or transport to definitive care, to patients with illnesses and injuries which the patient, or the medical practitioner, believes constitutes a medical emergency...

    • Police
      Police
      The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...

  • Funeral
    Funeral
    A funeral is a ceremony for celebrating, sanctifying, or remembering the life of a person who has died. Funerary customs comprise the complex of beliefs and practices used by a culture to remember the dead, from interment itself, to various monuments, prayers, and rituals undertaken in their honor...

  • Boeing
    Boeing
    The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

     Flight Test
    Flight test
    Flight test is a branch of aeronautical engineering that develops and gathers data during flight of an aircraft and then analyzes the data to evaluate the flight characteristics of the aircraft and validate its design, including safety aspects...

  • Health care
    Health care
    Health care is the diagnosis, treatment, and prevention of disease, illness, injury, and other physical and mental impairments in humans. Health care is delivered by practitioners in medicine, chiropractic, dentistry, nursing, pharmacy, allied health, and other care providers...

  • Logistics
    Logistics
    Logistics is the management of the flow of goods between the point of origin and the point of destination in order to meet the requirements of customers or corporations. Logistics involves the integration of information, transportation, inventory, warehousing, material handling, and packaging, and...

  • Hospitality
    Hospitality industry
    The hospitality industry consists of broad category of fields within the service industry that includes lodging, restaurants, event planning, theme parks, transportation, cruise line, and additional fields within the tourism industry. The hospitality industry is a several billion dollar industry...

  • Manufacturing
    Manufacturing
    Manufacturing is the use of machines, tools and labor to produce goods for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...

  • Military
    Military
    A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

  • Retail
    Retail
    Retail consists of the sale of physical goods or merchandise from a fixed location, such as a department store, boutique or kiosk, or by mail, in small or individual lots for direct consumption by the purchaser. Retailing may include subordinated services, such as delivery. Purchasers may be...

  • Telecommunications
    • Television
      Television
      Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...

    • Radio broadcasting
  • Transportation
    • Railroads
  • Security
    Security
    Security is the degree of protection against danger, damage, loss, and crime. Security as a form of protection are structures and processes that provide or improve security as a condition. The Institute for Security and Open Methodologies in the OSSTMM 3 defines security as "a form of protection...

  • Public utilities
    Public utility
    A public utility is an organization that maintains the infrastructure for a public service . Public utilities are subject to forms of public control and regulation ranging from local community-based groups to state-wide government monopolies...

    • Nuclear power
      Nuclear power
      Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...

    • Fossil fuel
      Fossil fuel
      Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...

    • Solar
      Solar power
      Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...

      , wind
      Wind power
      Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....

      , and hydro
      Hydropower
      Hydropower, hydraulic power, hydrokinetic power or water power is power that is derived from the force or energy of falling water, which may be harnessed for useful purposes. Since ancient times, hydropower has been used for irrigation and the operation of various mechanical devices, such as...

       power

See also

  • Circadian rhythm sleep disorders
  • Eight-hour day
    Eight-hour day
    The eight-hour day movement or 40-hour week movement, also known as the short-time movement, had its origins in the Industrial Revolution in Britain, where industrial production in large factories transformed working life and imposed long hours and poor working conditions. With working conditions...

  • Hospital
    Hospital
    A hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....

  • Schedule (workplace)
    Schedule (workplace)
    A schedule, often called a rota, is a list of employees who are working on any given day, week, or month in a workplace. A schedule is necessary for the day-to-day operation of any retail store or manufacturing facility. The process of creating a schedule is called scheduling...

  • Sleep
    Sleep
    Sleep is a naturally recurring state characterized by reduced or absent consciousness, relatively suspended sensory activity, and inactivity of nearly all voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and is more easily reversible than...

  • Split shift
    Split shift
    Split shift is an employment schedule, a type of shift work where a person's normal work day is split into two or more segments; for example a person may work from 5 a.m. to 9 a.m. and then have a break until 3 p.m. at which point he might return to work until 7 p.m...

  • Timebar scheduling
    Timebar scheduling
    Timebar scheduling is a method of staff scheduling that may be adopted by organizations with highly variable staff scheduling requirements.The primary advantage of timebar scheduling is that it makes it visually clear how many employees will be working or on break at any given time.To implement...


Further reading

  • Knutsson, A., Åkerstedt, T., Jonsson, B.G. & Orth-Gomer, K. (1986) 'Increased risk of ischaemic heart disease in shift workers'. Lancet, 2(8498), 89–92.
  • Burr, Douglas Scott (2009) 'The Schedule Book', 'ISBN 978-1-4392-2674-2'.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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