A part-time contract is a form of employment that carries fewer hours per week than a full-time job. They work in shifts. The shifts are often rotational. Workers are considered to be part-time if they commonly work fewer than 30 hours per week. According to the International Labour Organization, the number of part-time workers has increased from one-fourth to a half in the past 20 years in most developed countries, excluding the United States. There are many reasons for working part-time, including the desire to do so, having one's hours cut back by an employer and being unable to find a full-time job. The International Labour Organisation Convention 175 requires that part-time workers be treated no less favourably than full-time workers.
In some cases the nature of the work itself may require that the employees be classified part as part-time workers. For example, some amusement parks are closed during winter months and keep only a skeleton crew on hand for maintenance and office work. As a result of this cutback in staffing during the off season, employees who operate rides, run gaming stands, or staff concession stands may be classified as part-time workers owing to the months long down time during which they may be technically employed but unable to work.
"Part-time" can also be used in reference to a student (usually in higher education) who takes only a few courses, rather than a full load of coursework each semester.
In the EU, there is a strong East/West divide, where: "in Central and Eastern European countries part-time work remains a marginal phenomenon even among women, while the Western countries have embraced it much more widely." The highest percentage of part-time work is in the Netherlands (see below) and the lowest in Bulgaria. There is also a gap between women (32.1% EU average in 2015) and men (8.9%).
The Netherlands has by far the highest percentage of part-time workers in the EU and in the OECD. In 2012, 76.9% of women and 24.9% of men worked part-time. The high percentage of women working part-time has been explained by social norms and the historical context of the country, where women were among the last in Europe to enter the workforce, and when they did, most of them did so on a part-time basis; according to The Economist, fewer Dutch men had to fight in the World Wars of the 20th century, and so Dutch women did not experience working for pay at rates women in other countries did. The wealth of the country, coupled with the fact that "[Dutch] politics was dominated by Christian values until the 1980s" meant that Dutch women were slower to enter into the workforce. Recent research led by professor Stijn Baert (Ghent University) debunked the idea that part-time work by students is an asset for their CV in respect of later employment chances.