Add or subtract days

What the result means

Adding or subtracting calendar days walks the civil calendar, weekend by weekend. It answers “what date is 23 days from now?”, not “what date is 23 business days from now?”. Contracts, cooling-off periods and “14 days to return” clauses are often calendar days even when people assume they skip Saturday.

How it is calculated

Result = start ± n calendar days

• start: The date you type, interpreted as a calendar date rather than a time of day.
• n: A whole number of days to add or subtract.

The date is stored as year-month-day and advanced in UTC days so a daylight-saving transition cannot skip or repeat a calendar date.

Worked example

23 days from 19 August 2026

A 23-day notice period starts on Wednesday 19 August 2026 and is counted in calendar days.

Start

19 August 2026 (Wednesday)

Add 23 calendar days

Includes the two intervening weekends

Result

11 September 2026 (Friday)

Eleven September is 23 midnights later, not 23 weekdays later. If the contract had said business days, the result would be later still once Labour Day in some states is considered.

Calendar days include the weekend. Business days do not.

A 14-day cooling-off period that starts on a Friday ends on a Friday a fortnight later, Saturday and Sunday included. A 14-business-day period starting the same Friday skips two weekends and any public holiday, and can land more than three weeks later. The two phrases are not interchangeable, and Australian contracts usually define which one they mean.

If the deadline is a working day in a particular state, use the business days calculator and pick that state. This page will still count Saturday, Sunday and the Melbourne Cup.

Daylight saving cannot skip a date here

The date is stored as a year-month-day and advanced in UTC days, so the spring-forward hour in Sydney or Melbourne cannot jump the result from Saturday to Monday. You are counting midnights on the civil calendar, not hours on a wall clock.

That also means this tool will not tell you 3pm Tuesday plus 36 hours. For a countdown in whole days, use the countdown calculator. For the span in years, months and days, use date difference.

Questions