Dates

Use the format “[Date] [Month] [Year]” (depending on what information you have) written out with no commas. If the day of the week is relevant, then put it before the date. No “st”, “nd”, “rd” and “th”.

12 March 2014
Monday 3 March 2014

Write out months in full. If space is limited (such as in a table) use the shortened version with no punctuation, but not for June and July. Do not use shortened versions of months in titles.

Jan
Apr
Sept
Retail sales in Great Britain: September 2017

Date spans

Use the format “[date] to [date]”. If using months, repeat the year after each month if the period spans years.

2009 to 2010
July to September 2014
July 2013 to September 2014

For a period between two dates, use the format “between [date] and [date]”.

between 1986 and 2014
between July and September 2014

Decades

Decades should only have an apostrophe when they are a possessive, not a contraction.

a 1960s’ child
the 1960s were great

Centuries

Use ordinal numbers.

21st century

Quarters

Define the quarter, the months covered, and the year. Explain which months are included in the quarter in the first instance of each section, and only include the quarter and year in every subsequent instance. Abbreviate the months to three or four characters. In titles write the months in full and avoid using quarters.

Quarter 1 (Jan to Mar) 2019
Quarter 2 (Apr to June) 2019
Quarter 3 (July to Sept) 2019
Quarter 4 (Oct to Dec) 2019
The value of goods imported narrowed in Quarter 2 (Apr to June) 2019. Within imports of goods, the largest decreases recorded in Quarter 2 2019 were…

Financial years

For financial years, write the period out in full the first time you use it in each section, followed by the abbreviation FYE for “financial year ending” in brackets. After that, use the abbreviation. This will need to be written out in full again the first instance in each section of your article or page.

financial year ending (FYE) 2011
FYE 2011