Writing Dates in AP Style

Years should be expressed as numerals except at the beginning of a sentence.

Example: Nineteen sixty-nine was the year Neil Armstrong landed on the Moon. 🌙

Example: Apollo 11 was the spaceflight that first landed humans on the Moon in 1969. ☄

For the month-day date format, use cardinal numbers (one, two, three) rather than ordinal numbers (first, second, third). And a rule of thumb for writing a date with commas: In the month-day-year format, place commas after the day and the year. When writing a long-form date, use a comma after days of the week.

Example: NASA was founded on July 29. 🌛

Example: On July 29, 1958, NASA was founded. 🌝

Example: On Tuesday, July 29, NASA was founded. ⭐

When writing about whole centuries, do not use an apostrophe before s. Centuries are plurals, not possessives. When writing about decades, there is no need to put an apostrophe between the zero and the s — that would indicate a possessive.

Examples: The first exposition of rocket mechanics began in the 1800s. (not 1800’s). 💫

Example: Space exploration began in the ’50s. (not 50’s). 🌒

When writing this post, we referenced this blog post by our client, Grammarly.