Dates & time calculators
Date differences, business days, age-style calendar spans and working-day arithmetic, including Australian public holiday data by jurisdiction.
- Australian financial year calculatorSee which financial year a date falls in, and how many days remain in the current year.
- Business days calculatorCount Australian business days between two dates, or add and subtract working days, with national and state public holidays.
- Workdays per year calculatorCount weekdays minus public holidays in a calendar year for an Australian state or territory.
- Australian public holiday calendarList public holidays for a year in a chosen state or territory, including many observed-Monday rules.
- Days between datesCount the days, weeks, weekdays and weekends between two dates, plus an age-style years/months/days span.
- Add or subtract daysAdd or subtract a number of calendar days from a date, including month and year boundaries.
- Age calculatorCalculate age in years, months and days, and days until the next birthday.
- Countdown calculatorCount whole days until a date, or how many days ago a date was.
- Week number and day of weekSee the ISO week number, ISO week-year and weekday name for a date.
Date arithmetic looks trivial until a deadline depends on it. The two questions that cause the most trouble are whether a count includes both end dates, and whether a “day” means a calendar day or a business day — because a five business day notice period can land anywhere from Friday to the middle of the following week depending on the state and the time of year.
These tools are explicit about both. Business-day counts use the public holidays of a jurisdiction you choose, since holidays in Australia are set by each state and territory rather than nationally.
Which tool do you need?
- Counting the days, weeks or months between two dates: use the date difference calculator.
- Counting only working days, or adding working days to a date: use the business days calculator and pick your state.
- Adding or subtracting plain calendar days including weekends: use the date offset calculator.
- Checking which public holidays apply in a state this year: use the public holidays list.
- Working out an age or a span in years and months: use the age calculator.
Common questions
Does a business day count include public holidays?
No. A business day here is Monday to Friday excluding public holidays in the state or territory you select. Weekends never count. If a contract defines business day differently, its definition applies.
Is the count between two dates inclusive of both ends?
For business days, counting between two dates includes both ends, which matches Excel’s NETWORKDAYS. That convention is stated on the page, because an off-by-one is the most common source of disagreement about a deadline.
Why do the holidays change depending on the state I choose?
Public holidays are declared by each state and territory. Some are observed everywhere, such as Anzac Day and Christmas Day, while others such as Labour Day fall on different dates in different jurisdictions, and some exist in only one.
Before you rely on a result
Every calculator on this page shows the formula it used, the assumptions it made and the source of any regulated figure. Results are estimates and not professional advice — the disclaimer explains the limits, and the guides explain the reasoning in more depth.