Commas in Dates
Summary
Place a comma between day and year in dates written in the American date format (month-day-year). No comma is needed in the British date format (day-month-year).
- American: The highest temperature ever recorded on Earth was on July 10, 1913, at Furnace Creek, California.
- British: The warmest day in the UK was 25 July 2019.
No comma is necessary when only the month and the year are specified.
- July 2019 turned out to be the hottest month on record.
The general rule
Commas are used in dates written in American English but not British. The general rule in formal writing is to use commas in dates only when necessary.
- This photograph was published on May 21, 2021.
- This photograph was published on 21 May 2021.
In this article, we discuss the use of commas in various styles of dates.
American English
In the American date format, which is month-day-year, use commas before and after the year. This helps to typographically separate the day from the year.
- American: On June 24, 1947, an American pilot saw a string of nine UFOs in the sky.
- American: We took this photo on January 7, 2019, during a class trip to an apple farm.
- American: The first episode of the series aired at 8:30 p.m. EST on September 22, 1994.
Remember to “close” your commas. Style manuals, including the Chicago Manual of Style and AP Stylebook, recommend using commas in pairs to set off the year. A comma should appear both before and after the year.
- Poor: The launch on April 17, 1970 went perfectly.
Better: The launch on April 17, 1970, went perfectly.
British English
The British format for writing dates is day-month-year. The month is spelled out, and no comma is necessary between month and year.
- British: On 1 April 1901, six colonies federated to form the Commonwealth of Australia.
- British: A photo of a frog taken on 13 August 1951 won the prize.
- British: James’s ship landed on Mars on 29 February 2036.
In the British style of writing dates, a comma between month and year is not incorrect but unnecessary and usually omitted in formal writing.
Month and year
When only the month and the year are specified, commas are unnecessary and therefore omitted in both British and American English.
- Poor: By April, 2020, the virus had spread across the globe.
Better: By April 2020, the virus had spread across the globe. - Poor: The first indoor shopping mall was opened in October, 1956.
Better: The first indoor shopping mall was opened in October 1956.
The date spelled out
Dates may be spelled out in creative and other informal writing. Write the day as an ordinal number, but still use numerals for the year. A comma between month and year is unnecessary, though not incorrect.
- The Y2K bug was expected to destroy civilization on the first of January 2000.
- It was on the twenty-seventh of January 2019 that we first heard of the virus.
- The portal will close at midnight on the twenty-ninth of February 2060.