In this section: Standard date format | Regional considerations | Decades and centuries | Examples of formatting dates and time periods

Standard date format

Cochrane documents always use this format and sequence for dates:

  • day (numeral) month (always in full) year (four-digit numeral)

No additional punctuation or suffixes should be used.

Regional considerations

There are regional differences in the ways dates are expressed. Always use the standard format in Cochrane documents.

Be careful when referring to seasons, as they occur at different times of the year in different parts of the world.

Decades and centuries

Decades are always expressed as numerals, and century numbers may be expressed as numerals or written in full (e.g. '19th century' or 'nineteenth century').

Examples of formatting of dates and time periods

Note: the date formats in the examples below are for use in the text of Cochrane documents. Date formats to be used in references are described in the References.



1 May

May 1

1 May 2000

May 1 2000 or May 1, 2000

May 2000

7 November

7/11 (UK = 7 November; USA = 11 July)


1960’s or ‘60s

19th century or nineteenth century

19th century