The truth is there is nothing very complicated about the calculation of annual leave. Leave was to be calculated weekly and when it was taken it should be valued at the greater of the worker’s current wage or their yearly average. This had been true since 1948.
What was clarified in the 2003 Act was that if it was difficult to determine what an ordinary week was, for example, because they worked variable hours each week, then the worker should get the higher of their yearly average or the average of the last four weeks. This was explained in the Act in minute detail. No mistaken understanding could be taken from the plain language.
It has become clear that almost no major employer or payroll provider did this simple calculation. Many also did not include regular allowances that should have been.