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Working time concerns the hours of the day and the days of the week that work takes place. Most people have standard working hours between 0800 and 1800 on weekdays. But work also takes place at non-standard hours in the evening, at night and on weekends. Non-standard working times constitute an important part of the economy and society. Work at non-standard hours may have negative effects on the health and well-being of workers because of tiredness and problems of combining work and private life.

Distribution of non-standard working times in Europe

Working time is well documented in labour statistics. Mostly the number of working hours and the percentage of part-time contracts is documented. The incidence of non-standard working hours in the European Union (EU) is studied every five years by means of the European Working Conditions Survey (EWCS)[1]and data collected in the framework of the Labour Force Survey (LFS)[2]. According to the LFS[3]the share of part-timers in total employed people aged 20-64 increased significantly between 2009 and 2013 but declined slightly in the following 5 years (2013-2018) and and then held steady in 2019. However, in 2020, when the COVID-19 pandemic impacted the European Union labour market, the share of part-time workers dropped to 17.3%, and this decline continued, reaching 17.0% in 2022 (figure 1)

Figure 1: Part-time employment

Source: [3]

In 2022, 27.8% of employed women worked part-time, compared to only 7.6% of employed men. There is a considerable variation in part-time work between European countries. In the Netherlands more than 1 in 5 employed people were working part-time in the Netherlands 38.4 %, Austria (30.1 %), Germany (27.9 %), Belgium (23.0 %) and Denmark (20.9 %). The lowest shares were found in Bulgaria, Slovakia and Romania where less than 4 % of employed people were part-timers and less than 5 % of employed women[3]

Between 2013 the average working week has fallen from 36.8 hours in 2013 to 36.2 in 2022 (figure 2)[4]. The number refers to the hours people ‘actually’ spent on work activities in their main job. The average number of working hours was lowest in 2020 during the COVID-19 pandemic and has been slowly increasing since then, but it remains significantly lower than before the pandemic[4]. The largest group of workers has an average working week of between 40 and 42 hours per week (38.4%), followed by those with an average working week of less than 35 hours per week (27.9%) and those working between 35 and 40 hours (17.7%). Nevertheless, there are workers who work longer working weeks. 16% work more than 42 hours a week of which almost half work more than 50 hours[5].

Figure 2: Average number of actual weekly hours of work in the main job (2013 – 2022)

Source: [4]

The European Working Conditions Telephone Survey (EWCTS, 2021)[6] identifies four types of working time that are generally considered unsocial: regularly working in one’s free time, regularly working at night, working long hours and regularly being required to work at short notice.

Night and shift work

A fifth of workers (21%) in the EU27 reported doing night work in 2021[6]. It was more common among men than women (25% versus 17%) and in middle and younger age groups than in older age groups. In terms of employment status, night work was more common among self-employed and temporary workers. In terms of occupations, night work was most common in security-related occupations, such as workers in the armed forces, workers in protective services and also in care occupations such as medical staff.

Long working hours

The term ‘long working hours’ may refer to working days that are longer than eight hours and working weeks that are longer than 40 hours, but also to working days longer than 10 or 12 hours or working weeks longer than 48 hours. In section 2.2 it will be outlined that, in particular in Anglo-Saxon and east Asiatic countries, long working days of 12 and more hours occur. In Europe long working hours are often related to overtime and extended working hours in the case of compressed working weeks[7]According to the EWCTS, 17% of workers reported that their usual working hours were 48 hours or more in 2021[6]. More than one in four skilled agricultural workers, managers, drivers and machine operators worked very long hours. More men than women reported long working weeks in paid work. The proportion of workers who reported working 48 hours or more per week varied widely by country, with 34% of workers in Greece, 26% in Romania, 24% in Poland and 23% in the Czech Republic, but only 10% of workers in the Netherlands and 9% in Denmark.

Working in free time

Working during one's leisure hours is one way the boundaries between work and home are blurring. This trend is largely due to the influence of technology and the rise of digital workplaces. Individuals may engage in work-related activities during their free time for various reasons, such as completing supplementary tasks in preparation for their jobs or addressing unforeseen urgent matters. However, often, they do so just to keep on top of their everyday tasks. The practice of working in one’s free time is most widespread within the education (36%) and agriculture sector (31%).  More than a third of skilled agricultural workers (36%) reported doing so regularly, as did 29% of managers and 25% of professionals[6].

Working at short notice

Having to come to work at short notice makes working hours unpredictable and a good work-life balance more difficult. The EWCTS data[6] show that workers in the youngest age group, 16-24 years old (21%), and those with a low level of education (23%) were proportionally more likely to say they had to come to work at short notice than those aged 56 and over (12%) and those with a higher level of education (12%). Workers with managerial responsibilities were also more likely to be called to work at short notice.

Table: Working time arrangements – Unsocial work schedules EU27 (% of respondents) (EWCTS 2021)

 Total (%)Men (%)Women (%)
Working at night (sometimes or more often)212517
Long working hours (> 48 hours/week)172111
Working in free time (several times a week or more)161617
Working at short notice (several times a month or more)141512

Source: [6]

Work and private life

Work at non-standard hours may cause problems with regards to reconciling work and family life. In 2021, 81% of people across the EU27 reported that their working hours fitted in either well or very well with their family or social commitments[6]. Combining work and private life is less often a problem in north and west European countries.


Effects of non-standard working times on health and well-being

There have always been workers who needed to work at night and at times when most people are free. But in the industrial revolution the invention of the steam engine and the light bulb made it possible to organise massive amounts of workers to work during all 24 hours of the day and seven days of the week. From that time the negative effects of, in particular, night work and long working hours became visible. Nowadays a huge body of research confirms these effects. Only some of these studies can be summarized here.

Night and shift work

The negative effect of night work on health is related to the biological clock of human beings, which are set to day activity. Working at night is more exhaustive than working in the daytime. Body functions become less active due to hormonal secretion[8]. Additionally, sleeping in the daytime is less restorative because body functions are set to optimal activity. Most people will not experience serious negative effects after one night of work, but with a higher number of night shifts in succession problems emerge such as: fatigue[9], mistakes and accidents[10], and also due to reduced lighting, decreased productivity[11], and emotional exhaustion and job stress[12]. Also the immune system becomes less effective so that people are more vulnerable to health problems and exposure to dangerous substances[13] . In the long run cancer is related to night work, in particular breast cancer. The International Agency for Research on Cancer (IARC) concluded that night shift work is probably carcinogenic to humans (Group 2A carcinogen)[14] [15]. Night work may also have negative effects on sleep duration, smoking, no exercise and obesity[16], and on eating habits leading to gastrointestinal and nutritional problems[17].

Long working hours

In the literature the negative health impact of long working hours is most often confirmed when working days last 10 hours or more and working weeks last 48 hours or more[18]. Systematic reviews and meta-analyses conducted by World Health Organisation (WHO) and the International Labour Organization (ILO)[19], show an increased risk of ischaemic heart disease and stroke among people working long hours (≥55 hours/week), when compared with people working standard hours (35-40 hours/week). These studies carried out in the framework of the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury show that around 9% of the global population were working at least 55 hours per week in 2016. Furthermore, an estimated 745,000 deaths and 23.26 million disability-adjusted life years (DALYs ) were attributable to these long working hours. DALYs are a standard measure of the number of years lost due to ill-health, disability or early death. This total burden was roughly equally split between the two causes, with ischemic heart disease and stroke accounting for 47% and 53% of deaths, respectively. Based on these estimates, WHO/ILO identified exposure to long working hours as the risk factor with the greatest work-related disease burden[20].

The effects of long working hours are well established in the literature[21] [22]. Research from Eurofound[23] shows that regular long working days and weeks are associated with exhaustion, and also with poorer general self-rated heath, sleep quality and well-being. Long working hours have harmful effects on both the physical and the mental health of workers. Furthermore, the greater the exposure, the greater the risk. Although the exact mechanisms that leading to illness remain uncertain, the majority of research suggests that endocrinal changes and alterations in the central nervous system are linked to chronic stress arising from extended workdays and related lifestyle factors. Prolonged working hours tend to have a detrimental impact on sleep quality, as they disrupt sleep patterns unfavourably. Extended work hours translate to reduced opportunities for rest, diminished sleep duration, and increased fatigue, particularly when overtime is consistently prolonged. The effects seem to be exacerbated when workers do not feel fairly compensated for their efforts[23] .

Platform work

Platform work is generally associated with a high degree of autonomy, flexibility and self-scheduling of working time. However, platforms can also exercise control over the time as well as over the tasks performed. The degree of autonomy that platform workers enjoy varies significantly across the different types of platform work and the platforms’ terms and conditions (e.g. algorithmic task assignment)[24].

Work and private life

Work at non-standard times may cause stress and emotional problems[12]. Employees on non-standard work shifts reported significantly higher overall burnout, emotional exhaustion, job stress and health problems than employees with day work. 

These problems may also emerge from the tension of not being able to combine work and private life, or may continue in private life. Presser[25] found that working in the evening, at night, in the weekend, and/or with rotating schedules affects the likelihood of marriages ending in separation or divorce within approximately five years. Nabe-Nielsen and colleagues[26] found that a misfit between working time preferences and actual work at non-standard times was associated with an increased dissatisfaction with working hours and/or an increased intention to leave the workplace because of one's working hours. Non-standard working hours can be in particular disruptive for work–life balance when employees are in a precarious employment situation with causal or temporary work, while regular and predictable non-standard working hours and non-extended working hours can contribute to a better work–life balance[7].

The increase of telework, in general, has afforded employees greater flexibility to adapt their working hours and location according to their personal circumstances, thereby enhancing work-life balance. Conversely, it has also contributed to the blurring of boundaries between work and private life making working hours not always well defined and, in some cases, leading to overtime and longer working hours[23]. Advancements in communication technologies and the widespread use of smartphones have transformed the idea of being 'constantly on call' into a reality for many professionals, as continuous remote access can exert pressure on workers to always remain reachable. The expectation that workers should be available virtually around the clock for online or mobile communication has a significant impact on people's daily lives and is considered potentially hazardous to workers’ health[27].

Individual differences and individual choices

Individual choices of employees are often related to career decisions and decisions related to the combination of work and private life. Having a health care job, for instance, often also implies working at night and at the weekend. Family care may be an important factor for working at non-standard times, in particular when the partner has a standard day job and takes over care responsibilities. 

Individual differences related to non-standard working times often have weak correlations in research. One reason for the reduced visibility of individual differences is that people differ strongly in physical constitution and health status which leads to health selection on the labour market. This means that people who dislike or are not able to work during non-standard hours or with long working hours are not likely to apply for these jobs. On the other hand, people tend to leave the job when problems related to non-standard working times or long working hours emerge. Only people with good physical condition and strong motivation are able keep their job with non-standard working times for a long time (healthy worker effect). This is for instance visible in the literature in the often good health conditions of older shift work groups. Young age is often considered to be related to better shift work tolerance[28].

Overview of intervention techniques

Optimal intervention techniques may prevent negative effects of non-standard working times. Four ways of influencing the negative effects of working time are distinguished.

The role of governments and social partners

Governments regulate working time by law. In Europe this is regulated by the EU’s Working Time Directive (2003/88/EC)[29] or some other sectoral regulations. Under the EU’s Working Time Directive, each member state must ensure that every worker is entitled to:

  • a limit to weekly working time, which must not exceed 48 hours on average, including any overtime.
  • a minimum daily rest period of 11 consecutive hours in every 24.
  • a rest break during working time, if the worker is on duty for longer than six hours.
  • a minimum weekly rest period of 24 uninterrupted hours for each seven-day period, which is added to the 11 hours of daily rest.
  • paid annual leave of at least four weeks per year.
  • extra protection in the case of night work (for example, average working hours must not exceed eight hours per 24-hour period; night workers must not perform heavy or dangerous work for longer than eight hours in any 24-hour period; there should be a right to free health assessments and in certain situations, to transfer to day work).

Directive 2019/1152/EU of the European Parliament and of the Council of 20 June 2019 on transparent and predictable working conditions in the European Union[30] establishes minimum rights applicable to every worker in the European Union. All workers have the right to working conditions which respect their health, safety and dignity, to a limit on maximum working hours, to daily and weekly rest periods and to an annual period of paid leave. The Directive also establishes a number of workers' rights such as the right to predictability of work: workers whose work pattern is entirely or mostly unpredictable shall benefit from a minimum level of predictability through the provision of reference hours and days (i.e. time slots during which work can take place at the request of the employer) and reasonable minimum notice periods (i.e. the period of time between when a worker is informed of a new work assignment and when the assignment starts).

In the 20th century social partners achieved an important role in the negotiation on working time and financial compensation by social agreements OSH in general. Nowadays working time is an important term of employment, directly after salary OSH Management and organisation. In these social negotiations interests may be balanced to prevent negative effects. Trade unions may negotiate better OSH situations and may convince employers to abandon too much night work and overtime, because increased tiredness lowers the production capacity of employees. The salary of employees is increased when working non-regular hours and overtime, but they suffer more because of increased tiredness and a negative work–life balance. Trade unions may be able to prevent too much irregularity and prevent sickness and disability in the long run.


Rosters are important tools to regulate non-standard working times. Rostering is necessary when company production times exceed the workday of the employees or when the workflow is irregular. This mostly is the case when the company continues its activity in the evening, at night, and/or at the weekend. Rosters often involve a rotating sequence where employees alternately work in the morning, afternoon, evening, at night and/or at the weekend.

There is a huge amount of roster variants. An important distinction is regular versus irregular rosters. In regular rotating rosters the same number of employees is staffed during all hours. Regular rosters are mostly found in industry (for instance: chemical, metal and automotive companies). Irregular rosters are applied when the staffing need varies over the day. They are applied, for instance, in health care facilities where most activity takes place during the day, and less staff is needed in the evening, at night and/or at the weekend.

Rosters can be constructed in such a way that they reduce the negative effects on health and work–life balance. Knauth and Hornberger[31] give an overview of roster rules from this point of view. Examples of these rules are that the maximum number of consecutive shifts has to be three, that forward rotation (first morning shifts, then evening shifts and then night shifts) is preferred to backward rotation, and that after a night shift there should be at least two days off. The maximum number of consecutive shifts should be 5–7. Garde et al.[32] also recommended that shift intervals should exceed 11 hours and the duration of shifts should be limited to 9 hours. Pregnant women should not work more than one night shift in a week. Bambra and colleagues[33] reviewed 26 shift work interventions and found that three factors are most effective considering health and work-life balance: 

  1. switching from slow to fast rotation;
  2. changing from backward to forward rotation; and
  3. self-scheduling of shifts.

Self-scheduling or self-rostering

Most rosters are prearranged by social agreement[34], but worked out at the organisation level. This gives employees a chance to influence their personal roster by formulating roster preferences. Most companies comply to this and also to informal exchange of shifts among employees, as far as this does not interfere with the interests of the organisation. This practice can be further enhanced by allowing employees to ‘self-roster’. With self-rostering (also called self-scheduling, prioritised working hours or self-selected working hours), employees may select working hours which fit their personal needs and preferences.

Several studies have been carried out[25] [35] that indicate that control over working hours is associated with improved well-being. But also a warning is given, because employees may not change their working hours or choose working hours which do not favour health. 

Technical and organisational solutions

As an alternative to making use of flexible working hours, companies can also consider a number of other organisational measures to meet the fluctuations in production demand. Examples are: flexible staffing of internal personnel over different work places or functions, hiring external personnel, ‘flexible working hours’ by giving workers the possibility to decide about the exact time of starting and finishing work, applying logistic solutions such as stockpiling, and reconsidering the production process. However, in a number of cases this is not possible, because production processes require continuous operation or technical investment is too high.

Also, temporary alleviating solutions to improve personnel functioning are possible. Pallessen and colleagues[36] reviewed a number of countermeasures to reduce the negative effects of night work. They found research supporting the positive effects of applying bright light therapy, melatonin administration, naps (small periods of sleep during working time), use of stimulants to improve wakefulness, use of hypnotics to improve daytime sleep, and proper work scheduling. But it is unknown if these effects have long-term consequences. 


Working time, specifically its duration and organisation, contributes to the quality of work in two ways. On the one hand, working time affects workers' health and well-being. Long working hours and poorly organised working hours pose a health risk, and the extent to which workers are exposed to workplace risks increases with the duration of work. On the other hand, a good balance between working time and non-working time throughout the career is essential for workers to be able and motivated to work and continue working until retirement.

Working time has received considerable attention and has been regulated by the EU to protect workers from excessively long and atypical working hours. The rise of a-typical employment forms such as platform work and digital technologies has led to an increased focus in policy discussions and regulations on the predictability of working hours and the 'right to disconnect'.


[1] Eurofound – European Foundation for the Improvement of Living and Working Conditions, European Working Conditions Survey (EWCS). Available at: 

[3] Eurostat. Part-time and full-time employment – statistics. Statistics explained, May 2023. Available at:

[4] Eurostat. Data: Average number of actual weekly hours of work in main job, by sex, age, professional status, full-time/part-time and economic activity (from 2008 onwards, NACE Rev. 2) LFSA_EWHAN2. Data browser. Available at: 

[5] Eurostat. Hours of work - annual statistics. Statistics explained, May 2022. Available at:

[6] Eurofound. Working conditions in the time of COVID-19: Implications for the future, European Working Conditions Telephone Survey 2021 series, 2022. Available at: 

[7] EU-OSHA – European Agency for Safety and Health at Work. Expert Forecast on Emerging Psychosocial Risks Related to Occupational Safety and Health. Report, 2007. Available at: 

[8] Lac, G., Chamoux, A., ‘Biological and psychological responses to two rapid shift work schedules’, Ergonomics, Vol. 47, No 12, 2004, pp. 1339-1349.

[9] Åkerstedt, T., Wright, K.P., ‘Sleep loss and fatigue in shift work and shift work disorder’, Sleep Med Clin, Vol. 4, No 2, 2009, pp. 257-271.

[10] Wagstaff, A.S., Sigstad-Lie J-A., ‘Shift and night work and long working hours − a systematic review of safety implications’, Scand J Work Environ Health, Vol. 37, No 3, 2011, pp. 173–185.

[11] Folkard, S., Tucker, P., ‘Shift work, safety and productivity’, Occupational Medicine, Vol. 53, No 2, 2003, pp. 95-101.

[12] Jamal, M., ‘Burnout, stress and health of employees on non-standard work schedules: a study of Canadian workers’, Stress and Health, Vol. 20, No 3, 2004, pp. 113-119.

[13] Knutsson, A., ‘Health disorders of shift workers’, Occupational Medicine, Vol. 53, No 2, 2003, pp. 103-108.

[14] IARC - International Agency for Research on Cancer, ''Shiftwork'', Monographs, volume 98, 2010. Available at: 

[15] Erren, T.C., Morfeld, P., Groß, J.V. et al. IARC 2019: “Night shift work” is probably carcinogenic: What about disturbed chronobiology in all walks of life?. J Occup Med Toxicol 14, 29 (2019). Available at: 

[16] Bushnell, P.T., Colombi, A., Caruso, C.C., Tak, S.W., ‘Work schedules and health behavior outcomes at a large manufacturer’, Industrial Health, Vol. 48, No 4, 2010, pp. 395-405.

[17] Knutsson, A., Bøggild, H., ‘Gastrointestinal disorders among shift workers’, Scand J Work Environ Health, Vol. 36, No 2, 2010, pp. 85-95.

[18] Hulst, M. van der., ‘Long work hours and health’, Scand J Work Environ Health, Vol. 29, No 3, 2003, pp. 171-188.

[19] WHO/ILO joint estimates of the work-related burden of disease and injury, 2000-2016: technical report with data sources and methods: Geneva: World Health Organization and the International Labour Organization, 2021. Available at: 

[20] WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury. Available at: 

[21] Kivimäki, M., Jokela, M., Nyberg, S. T., Singh-Manoux, A., Fransson, E. I., Alfredsson, L., ... & Virtanen, M. Long working hours and risk of coronary heart disease and stroke: a systematic review and meta-analysis of published and unpublished data for 603 838 individuals. The lancet, 2015, 386(10005), 1739-1746. Available at: 

[22] Wong, K., Chan, A. H., & Ngan, S. C. The effect of long working hours and overtime on occupational health: a meta-analysis of evidence from 1998 to 2018. International journal of environmental research and public health, 2019, 16(12), 2102. Available at: 

[23] Eurofound. Overtime in Europe: Regulation and practice, Publications Office of the European Union, Luxembourg, 2022. Available at: 

[24] Eurofound. Platform work: Autonomy and control. Available at: 

[25] Presser, H.B., ‘Nonstandard work schedules and marital instability’, Journal of Marriage and Family, Vol. 62, No 1, 2000, pp. 93-110.

[26] Nabe-Nielsen, K., Kecklund, G., Ingre, M., Skotte, J., Diderichsen, F. & Gardea, A.H., ‘The importance of individual preferences when evaluating the associations between working hours and indicators of health and well-being’, Applied Ergonomics, Vol. 41, No 6, 2010, pp. 779-786.

[28] Saksvik, I.B., Bjorvatn, B., Hetland, H., Sandal, G.M. & Palessen, S., ’Individual differences in tolerance to shift work – A systematic review’, Sleep medicine reviews, Vol. 15, No 4, 2011, pp. 221-235.

[29] Directive 2003/88/EC of the European Parliament and of the Council of 4 November 2003 concerning certain aspects of the organisation of working time. Available at: 

[30] Directive 2019/1152/EU of the European Parliament and of the Council of 20 June 2019 on transparent and predictable working conditions in the European Union. Available at: 

[31] Knauth, P., Hornberger, S., ‘Preventive and compensatory measures for shift workers’, Occupational Medicine, Vol. 53, No 2, 2003, pp. 109-116.

[32] Garde, A. H., Begtrup, L., Bjorvatn, B., Bonde, J. P., Hansen, J., Hansen, Å. M., ... & Sallinen, M. How to schedule night shift work in order to reduce health and safety risks. Scandinavian journal of work, environment & health, 2020, 46(6), 557. Available at: 

[33] Bambra, C.L., Whitehead, M.M., Sowden, A.J., Akers, J. & Petticrew, M.P., Shifting Schedules. ‘The health effects of reorganizing shift work’, Am J Prev Med, Vol. 34, No 5, 2008, pp. 427-434.

[34] European Commission. Employment, Social Affairs & Inclusion, Working Conditions. Available at: 

[35] Garde, A.H., Nabe-Nielsen, K., Aust, B. ‘Influence on working hours among shift workers and effects on sleep quality – an intervention study’. Applied Ergonomics, Vol. 42, No 2, 2011, 238-243.

[36] Pallessen, S., Bjorvatn, B., MagerØy, N., Saksvik, I.B., Waage, S. & Moen, B.E., ‘Measures to counteract the negative effects of night work’, Scand J Work Environ Health, Vol. 36, No 2, 2010, pp. 109-120.

Further reading

EU-OSHA – European Agency for Safety and Health at Work. Family issues and work-life balance. E-fact 57, 2012. Available at: 

ILO – International Labour Organisation. Working Time and Work-Life Balance Around the World. Available at: 

EU Commission. Working Conditions - Working Time Directive. Available at: 

Eurofound. Working time. Available at: 

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