Holiday pay continues to be a developing area through case law. The case of Flowers –v- East of England Ambulance Trust revisited the question of whether voluntary overtime should be taken into account when calculating holiday pay. The facts of the case involved ambulance crews whose contracts provided for ”non-guaranteed” overtime, which was mandatory, and also “voluntary” overtime, which was voluntary – both of which occurred on an entirely irregular basis. The ambulance crew argued that their “normal” remuneration should include “voluntary” overtime. The EAT agreed that if voluntary overtime is paid over a sufficient period then it should be taken into account when calculating holiday pay. However, it said it was a matter of fact for the Employment Tribunal to establish whether the individuals “voluntary” overtime was over a “sufficient period of time”. Therefore, the EAT followed the existing decision of Dudley Metropolitan Borough Council –v- Willetts.