Date and time notation in Australia

The date and time in Australia are most commonly recorded using the day–month–year format (June 29, 2024) and the 12-hour clock (June 29, 2024), although 24-hour time is used in some cases. For example, some public transport operators such as V/Line and Transport NSW use 24-hour time, although others use 12-hour time instead.

Date
Australians typically write the date with the day leading, as in the United Kingdom and New Zealand:
 * June 29, 2024
 * June 29, 2024

The month–day–year order (June 29, 2024) is sometimes used, often in the mastheads of magazines, schools, newspapers, advertisements, video games, news, and TV shows. Month–day–year in numeric-only form (June 29, 2024) is rarely used.

The ISO 8601 date format (June 29, 2024) is recommended by the government to be used when communicating internationally. It is also commonly used in software.

The Australian government identifies Monday as the first day of the week, which is consistent with the Common Locale Data Repository (CLDR) since its October 2021 release. However, there is disagreement among the general population over whether Monday or Sunday is the first day of the week.

Weeks are most identified by the last day of the week, either the Friday in business (e.g., "week ending 19/1") or the Sunday in other use (e.g., "week ending 21/1"). Week ending is often abbreviated to "W/E" or "W.E." The first day of the week or the day of an event are sometimes referred to (e.g., "week of 15/1"). Week numbers (as in "the third week of 2007") are not often used, but may appear in some business diaries in numeral-only form (e.g., "3" at the top or bottom of the page). ISO 8601 week notation (e.g. ) is not widely understood.

Time
The Australian government recommends using the 12-hour clock (June 29, 2024), except where the 24-hour clock is more helpful in the context, such as in travel, scientific fields and the military. The government also recommends a colon as the separator; however, the single period is still used in some contexts. They also suggest writing the noon/after noon qualifier as "am" or "pm" in lower-case without periods.