Working (laboring) time is the period of time that a person spends at paid labor. Unpaid labor such as personal housework or caring for children or pets is not considered part of the working week.

Many countries regulate the work week by law, such as stipulating minimum daily rest periods, annual holidays, and a maximum number of working hours per week. Working time may vary from person to person, often depending on economic conditions, location, culture, lifestyle choice, and the profitability of the individual's livelihood. For example, someone who is supporting children and paying a large mortgage might need to work more hours to meet basic costs of living than someone of the same earning power with lower housing costs. In developed countries like the United Kingdom, some workers are part-time because they are unable to find full-time work, but many choose reduced work hours to care for children or other family; some choose it simply to increase leisure time.

Standard working hours (or normal working hours) refers to the legislation to limit the working hours per day, per week, per month or per year. The employer pays higher rates for overtime hours as required in the law. Standard working hours of countries worldwide are around 40 to 44 hours per week (but not everywhere: from 35 hours per week in France to up to 105 hours per week in North Korean labor camps) and the additional overtime payments are around 25% to 50% above the normal hourly payments. Maximum working hours refers to the maximum working hours of an employee. The employee cannot work more than the level specified in the maximum working hours law.

The World Health Organization and the International Labour Organization estimated that globally in 2016 one in ten workers were exposed to working 55 or more hours per week and 745,000 persons died as a result of having a heart disease event or a stroke attributable to having worked these long hours, making exposure to long working hours the occupational risk factor with the largest disease burden.