Acts Interpretation Act 1954

If a period beginning on a given day, act or event is provided or allowed for a purpose by an Act, the period is to be calculated by excluding the day, or the day of the act or event, and—

if the period is expressed to be a specified number of clear days or at least a specified number of days—by excluding the day on which the purpose is to be fulfilled; and

in any other case—by including the day on which the purpose is to be fulfilled.

If the time, or last day of a period, calculated forwards that is provided or allowed by an Act for doing anything falls on an excluded day, the time, or last day, is taken to fall on the next day later that is not an excluded day.

If the time, or earliest day of a period, calculated backwards that is provided or allowed by an Act for doing anything falls on an excluded day, the time, or earliest day, is taken to fall on the next day earlier that is not an excluded day.

If no time is provided or allowed for doing anything, the thing is to be done as soon as possible, and as often as the relevant occasion happens.

In this section—excluded day—

for filing or registering a document—means a day on which the office is closed where the filing or registration must or may be done; or

otherwise—means a day that is not a business day in the place in which the thing must or may be done.