21 August 2026

Business days across eight jurisdictions, and six different Christmases

Six of the eight Australian jurisdictions stop counting over a Christmas shutdown, and they do not agree on when it starts. Getting it wrong moves deadlines by a fortnight.

A deadline worked out on a desk calendar is a guess in any Australian jurisdiction, and in December it is a guess that is wrong by up to two weeks.

The shutdown is not a Victorian quirk

Six of the eight jurisdictions pause the business-day count over the Christmas period, with different windows. Western Australia, Victoria and Queensland begin around 22 December; New South Wales and Tasmania only from the 27th.

Serve the same payment claim on the same day in two states and you get two different response deadlines, and neither matches an ordinary calendar count.

South Australia is calculated, and never unflagged

The South Australian definition of a business day excludes "any other day on which there is a Statewide shut-down of the … building and construction industry". That is an event somebody declares, not a date, and no calendar models it.

VariationFlow computes South Australian dates on the ordinary rule and marks every one of them provisional. A declared shutdown makes the true date later than shown, so a deadline binding you is safe to treat as shown and the other side's default is not. The formal notice refuses to assert a South Australian date at all. A confident wrong date is worse than a flagged one, and this is the one place in the Australian engine where the flag never comes off.

The ACT was the one that was wrong

Until September 2026 the ACT was computed with no December exclusion at all, on the belief that its Act defined no business day. Its own dictionary excludes 27 to 31 December, the same five days as New South Wales, and every ACT deadline crossing late December was up to five days early. Reading the authorised text found it. Reading the code never would have.