This paper examines the impact of work-time regulation, introduced by the UK's New Labour governments (1997 to 2010). In doing so, we return to Marx's hypotheses regarding the length of the working day. These include the arguments that class conflict over the length of the working day is inherently distributional in a surplus-value sense and that workers often display a preference for reduced suggest the impact of these policy initiatives was broadly favourable, though the effect on men and women was different.