This monograph is a comparative study of the industrial relations and human resource implications of flexible working time arrangements between two similar organisations (in terms of size and function) in the UK and the Netherlands. The conception of flexible working time used in this study is taken to be a board term encompassing working patterns outside ?9 to 5'. The two organisations examined are not-for-profit plasma fractionators: the UK's BPL and the Dutch CLB. The monograph, drawing on developments in working time in the two countries and across the European Union, looks for observations of these trends in the organisations. The study shows that, despite some strong European trends towards convergence of working time arrangements, there are significant differences between both countries and between the two organisations studied. This is explained in terms of political, economic, social and cultural factors. Both organisations have forms of flexible working, however, in the UK this is employer driven, whereas in the Netherlands there is a firmer balance between meetings the needs of employer and employees.