Dates, times and time periods

Centuries

Centuries can be written in numbers or letters – just be consistent.

Examples

  • 21st century
  • twenty-first century.

Dates

The order for presenting dates is: day of the week, date (numeral), month (word), year. There is no punctuation. Don’t use ordinal numbers for full dates.

Write

Our next Open Day will be on Sunday 7 September 2021

Don’t write

Our next Open Day will be on Sunday, 7th September.

When referring to a date only, use an ordinal number (numeral with suffix st or th). Don’t format the suffix in superscript.

Write

They’ll deliver on the 20th.

Don’t write

They’ll deliver on the twentieth.

Days of the week

Spell out in full in text and use abbreviations in tables.

When referring to spans of days, use the pairing from/to.

Example

The office is open from Monday to Friday.

Decades

Don’t use an apostrophe when referring to a decade.

Write

Budgets remained stable in the 1990s.

Don’t write

Budgets remained stable in the 1990’s.

Historical periods (CE, BCE)

Use CE (Common Era) and BCE (Before the Common Era) rather than BC or AD. There is a space between
the number and the abbreviation.

Example

The first Egyptian pyramids were built around 2,500 BCE.

Months

Write months in full in general text. In tables, abbreviate the month/s if necessary, without a full stop after the abbreviation.

Time of day

  • Write the time of day in lower case without a space after the figure
  • Include a comma between the time and date/day
  • Use a colon to separate hours and minutes.

Examples

  • 10:30am, 28 August 2020
  • 10:30am, Friday 28 August 2020
  • 10am, Friday 28 August 2020
  • 10:00am, Friday 28 August 2020
  • The speech will start at 9:30am and end at 1:30pm
  • Your lecture will be from 9am to 11am.

Timespans

When referring to time spans, use the pairings from/to or between/and rather than an en dash.

The exceptions to this general rule are date ranges for:

  • financial years
  • terms of office
  • lifespan (birth and death).

Examples

  • I’ll arrive between 9:30 and 10:30am
  • Your lecture is from 11am to 1pm
  • Curtin University Strategic Plan 2017–21
  • John Curtin (1885–1945) was Australia’s 14th prime minister.