The subject of working time has been important to the work of the International Labour Organization since its inception. Some of the major challenges in this area remain those which have been important to working time policies since the adoption of the ILO's first Convention, the Hours of Work (Industry) Convention, 1919 (No. 1). Most significantly, these include the need to limit excessive hours of work and provide for adequate periods of rest and recuperation, including weekly rest and paid annual leave, in order to protect workers' health and safety. These concerns have been enshrined for many years in a wide range of international labour standards concerning working time. In particular, the problem of long working hours and the need for adequate rest remain of vital importance — not only in the developing world, but in many industrialized countries as well.

Over the last several decades a number of broad socio-economic trends have emerged which have had an enormous impact on working time. The process of globalization and the resulting intensification of competition, the associated development in information and communications technologies, and new patterns of consumer demand for goods and services in the '24-hour economy' have had a large impact on production methods and work organization. From the perspective of the enterprise, the drive to enhance the utilization of capital, reduce labour costs, manage human resources in innovative ways, and respond to diversifying customer demands have birthed enterprise strategies such as new methods of flexible production (just-in-time, lean production, etc.) and a much more flexible organization of work, including working time.

From the perspective of workers, there have been profound demographic changes, particularly the increasing entry of women into the paid labour market and the resulting increased feminization of the labour force; the related shift from the single 'male breadwinner' household to dual-earner households; and a growing concern over the quality of working life, particularly in the industrialized world. These various developments have shaped workers' needs and preferences in relation to working life, including in respect to the duration and timing of work, which vary according to worker characteristics — perhaps most significantly by gender — as well as over the life cycle of individual workers. All of these changes are reflected in a variety of working time arrangements which vary from conventional full-time, permanent, weekday work in terms of either their duration and/or timing: part-time work, flexi-time and 'time banking' accounts in which workers can credit or debit their hours just like money in a bank, working 'on call' (as and when needed), and the averaging of working time over periods of up to a year.

The end result of these developments is a growing diversification, decentralization and individualization of the hours that people work, as well as an often increasing tension between enterprises' business requirements and workers' needs and preferences regarding their working time. Thus, in addition to longstanding concerns about working time and workers' health and safety, new concerns have emerged relating to employment security and stability, wages and non-wage compensation, and workers' ability to balance their paid work with the rest of their lives.