. This historical perspective may become important if there is a lay-off from work, for example, or if there were to be a repeat of the three-day week experienced in the winter of 1973-74. The question became crucial at that time of whether employers were obliged to pay full wages and full salary for only three days’ work, bearing in mind that the calculation of earnings was by hour for manual workers and by year for salaried employees. This was notwithstanding that the intervals for actual payment, as a matter of convenience, were normally one week and one month, respectively. We can therefore see that the positions of wage- and salary-earners could differ in the 1970s as a result of nineteenth-century thinking on these matters. If the judiciary attach more importance to continuity in the law than in a future situation comparable to the three-day week, salaried workers would be treated much more favourably than wage-earners (for a full discussion, see Chap. 7).