What Is a Business Day?
Australian public holidays vary by state — a key factor in any business days calculation
A business day is generally understood to be any weekday — Monday through Friday — that is not a public holiday. In Australia, the definition varies slightly by state and territory, because public holidays are declared at both the federal and state levels. For example, a date that is a public holiday in Victoria may be an ordinary working day in Queensland.
Under Australian commercial law and the Acts Interpretation Act 1901, a business day typically means a day that is neither a Saturday, Sunday, nor a public holiday in the relevant jurisdiction. This definition is central to any business days calculator that aims to be legally accurate.
Why Business Days Differ From Calendar Days
The difference between business days and calendar days can be significant over any multi-week period. Consider a 30-calendar-day span: it will typically contain 20 to 22 business days depending on how weekends and public holidays fall. A 10-business-day notice period may span 14 calendar days or longer if public holidays intervene.
This distinction matters in many professional and legal settings. Payment terms such as "net 30" may refer to calendar days or business days depending on the contract. Court filing deadlines, construction handover dates, and HR notice periods almost always specify which measure applies.
Australian Public Holidays and Their Impact
Because Australia operates across six states and two territories, each with distinct holiday schedules, business day calculations are jurisdiction-sensitive. Key considerations include:
- National public holidays (New Year's Day, Australia Day, Good Friday, Easter Monday, Anzac Day, Christmas Day, Boxing Day) are observed across all states and territories, though substitute days may vary.
- State-specific holidays such as Melbourne Cup Day (Victoria), the Adelaide Cup (South Australia), and Queensland's Royal Queensland Show holiday affect calculations in those states only.
- Territory holidays add further variation — the ACT observes Family & Community Day, for example.
A business days calculator that accounts for Australian public holidays must allow users to select their state or territory to return accurate results.
How a Business Days Calculator Works
A business days calculator takes a start date and end date, then iterates through each calendar day in the interval. For each day, it checks two conditions:
- Is the day a Saturday or Sunday? If so, exclude it.
- Is the day a designated public holiday for the relevant jurisdiction? If so, exclude it.
The remaining days are business days. This process is simple conceptually but requires an up-to-date, jurisdiction-specific public holiday database to be accurate.
Worked Examples
Example 1 — Invoice Payment
An invoice issued on Monday 1 April 2024 with 14-business-day payment terms is due on Monday 22 April 2024. Note that the calculation skips two weekends and the Easter public holidays (Good Friday 29 March and Easter Monday 1 April — if the invoice date itself is a public holiday, the clock may not start until the next business day, 2 April).
Example 2 — Notice Period
An employment resignation submitted on Friday 14 June 2024 requiring 5 business days' notice expires on Friday 21 June 2024 (skipping the weekend of 15–16 June).
Example 3 — Construction Deadline
A 60-business-day construction milestone starting 1 July 2024 concludes on approximately 22 September 2024, after skipping 17 weekends and any public holidays that fall in Queensland during that period.
Business Day vs Calendar Day: Which Should You Use?
The correct measure depends entirely on the document or agreement that governs the calculation. Always read contracts, awards, and legislation carefully. When not specified, commercial practice in Australia typically defaults to calendar days, but legal documents often specify business days for notice and payment terms.
| Context | Measure | Reason |
|---|
| Employment notice period | Business days | Fair Work Awards specify business days |
| Invoice payment terms | Check the contract | May be calendar or business days |
| Court filing deadline | Business days (usually) | Courts typically count working days |
| Lease duration | Calendar days | Property law uses calendar months/days |
| Construction milestone | Business days | Work only occurs on working days |
Authoritative References
Official Australian government and legal sources referenced in this article.
Fair Work Australia: Public HolidaysOfficial Australian government resource for national and state public holiday entitlements and the definition of business days under employment law. ISO 8601 — ISO.orgInternational date standard referenced for business day calculation methodology and date formatting.
Frequently Asked Questions
Does Australia Day count as a business day?
No. Australia Day (26 January) is a national public holiday observed across all states and territories. When it falls on a weekend, a substitute weekday is observed, which also does not count as a business day.
Do I count the day I send a notice as day one?
This depends on the agreement or legislation governing the notice. Many Australian laws provide that the period begins the day after the notice is given. Always verify the starting point rule in the relevant document.
What happens to business day counts during Easter?
Easter includes Good Friday and Easter Monday as national public holidays, and Easter Saturday is a public holiday in some states. This can reduce the business days in that week to as few as two or three.
Is Saturday a business day in Australia?
Generally no. Most Australian businesses operate Monday to Friday. However, some industries (retail, hospitality) operate on weekends, and specific awards or contracts may define Saturday as a business day.