This chapter traces the growth of part-time working - its overall pattern, the extent to which it has been concentrated within certain sectors and groups of occupations, the reasons behind its growth. One of the aspects of part-time working which has attracted considerable attention in recent years is the concept of job-sharing, where two people jointly share the responsibilities of one full-time job. The increase in part-time working is one of the most marked changes in Britain's working time patterns in the past 20 years. A number of broad definitions exist including that of the International Labour Office which defines part-time as 'work on a regular and voluntary basis for a daily or weekly period of substantially shorter duration than current normal or statutory hours of work'. Early demand for job-sharing schemes has come particularly from individuals and feminist movements seeking a pattern of working time less closely geared to the interests of males in single wage-earner households.