Both the National Minimum Wage Regulations 1999 (NMW) and the Working Time Regulations 1998 (WTR) call for calculations of "working time", so there is a temptation to assume that the words mean the same thing in both provisions. But beware – there is a crucial difference when it comes to periods when a worker is on stand-by.
Contrast Baxter v Titan where, in the context of the NMW, periods a chauffeur spent away from home between assignments where he was able to sleep over at a hotel were not working time, with Wray v JW Lees & Co (Brewers) Ltd where periods where a temporary pub manager was required to remain on work premises but was permitted to sleep did not count for minimum wage but, it was accepted, could count as working time for the purposes of the WTR.
Broadly, you need to look at whether the worker is at required to be at work premises and awake for the purpose of working to count the time for NMW, but for calculating WTR working time, time spent on standby at work premises can count even when no actual work may be required. As these judgments demonstrate, it can be a confusing idea to get one’s head around, but the obvious starting point is to decide whether it is a working time or a minimum wage question that must be decided. In the case of any uncertainty we strongly urge you to contact us.