Where the time at which an officer is due to commence a rostered tour of duty is brought forward without due notice (less than 11 hours) so that they are required to commence duty on a day in which they have already completed their normal period of duty. The time for which they are on duty before the rostered commencement time shall be reckonable as overtime and also taken into account as part of that tour of duty. The force day commences at 7 A.M.

If the day were a rest day, then the overtime would be at double time for a minimum of 4 hours.

If you are given more than 11 hours notice of the duty change then your working day merely starts at the new time.