Build your own style guide: Dates and times

Styles have changed considerably in the last 10 years or so. How you display dates is up to you – and you might choose one style for formal writing and another for less formal documents or online content. Times are usually written without punctuation these days.

Dates

Style 1

Using ‘th’ etc. in dates is the traditional style and is still widely used, especially in formal writing. Note the use of commas.
Examples: on 4th January 2019 / by 2nd February 2019 / on Friday, 4th January 2019

When speaking, we add these words: the 4th of January. Do not use them when writing.

Style 2

Omitting ‘th’ etc. in dates is increasingly common.
Examples: on 4 January 2019 / by 2 February 2019 / on Friday, 4 January 2019

All styles

For periods of time, avoid apostrophes and spaces.
Examples: In the 1990s / 2016-2017

Warning: Writing dates as numbers is best avoided because some countries reverse the order. It is acceptable in spreadsheets and tables (although it might be helpful for users to note that your dates are day/month/year).
Examples: 4/1/2019 (in US and Canada: 1/4/2019)

Times

Style 1

A modern style has no full stops, spaces or zeros.
Examples: 9am / 2.45pm

Periods of time – there’s no need to use spaces.
Example: Open: 9am-2pm

Ensure there’s no confusion between 12pm and 12am.
Examples: noon / midnight

Style 2

The 24-hour clock is becoming more widely used – but you need to decide if you want to use punctuation or not.
Example 1: 9:00 / 15:00 / 14:45 / 24:00 / 12:00
Example 2: 0900 / 1500 / 1445 / 2400 / 1200

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By Plain English Ireland, for better business writing: www.plain-english.ie