In this case the ECJ considered how an employer should calculate holiday entitlement when part time workers increase their hours.
Mrs Greenfield, a care worker, took seven days' leave in July 2012, at which point she was working one day a week. This added up to seven weeks' leave, which exceeded her entitlement. Two months later, she increased her hours. When she requested a week's leave in November 2012, her employer refused her request, pointing out that she had exhausted her entitlement to paid annual leave in July 2012.
Ms Greenfield argued that leave already accrued and taken should be retrospectively recalculated using the increased hours to calculate her entitlement. Her employer disagreed, and the case was referred to the ECJ.
The ECJ ruled that, when a worker increases their hours, any statutory annual leave that has already accrued does not need to be recalculated retrospectively. Any leave taken in excess of the entitlement that applied under the previous working pattern can be deducted from the increased level of leave. However, going forward, holiday entitlement should be recalculated to reflect the new working pattern.
What this means for employers
This is a useful and sensible outcome for employers and it would have been very surprising if this broad principle had been decided another way. However, thornier questions about the detail of how employers should calculate holiday entitlement when working patterns change are outstanding and we may see more cases on this issue.