Like the majority of Generation Xers, I was born in the decade of disco, leisure suits, and questionable mustaches. Does that mean I was born in the 1970s, the ’70s, or the seventies? Today’s post answers that question by analyzing how to write decades as complete numerals and words as well as abbreviated numerals.
Should We Write Decades as Numerals or Words?
As a general rule, decades can always be written as complete numerals:
Dallas and big hair were popular in the 1980s.
The Brady Bunch and bell bottoms were popular in the 1970s.
In fact, The Associated Press Stylebook (AP style) doesn’t allow decades to be written as words.1 The Chicago Manual of Style (Chicago style), on the other hand, approves of decades written as words or numerals as long as the decades are identifiable through the surrounding content (so your readers don’t mistake the 1980s for the 1880s).2
Dallas and big hair were popular in the eighties.
The Brady Bunch and bell bottoms were popular in the seventies.
Chicago includes the caveat that the first decade (years 00 through 09) of a century shouldn’t be written as numerals because it may be confused with the entire century (e.g., the 1700s could be mistaken for the eighteen century).3 Although this caveat isn’t mentioned in our other primary style guides, we should all consider following Chicago on this issue to prevent confusion.
The Publication Manual of the American Psychological Association (APA style) doesn’t address decade formatting, but we can assume that APA followers should write decades as numerals because the manual recommends using numerals for all numbers greater than nine unless they start a sentence. In addition, the APA uses a decade written as a numeral in an example for another topic.4
Should We Write Decades as Abbreviated Numerals?
All the style guides mentioned above accept (or are silent on) decades formatted as abbreviated numerals prefaced by an apostrophe:
Game shows grew to prominence in the 1950s and ’60s.
Swing music was enjoyed in the 1930s and ’40s.
However, The Chicago Manual of Style (Chicago) indicates that decades written as abbreviated numerals (the ’60s) are less formal than complete numerals (the 1960s).5 Therefore, writers who follow Chicago or are concerned with formality should use complete numerals for decades in reports, proposals, and other professional documents where abbreviations may be inappropriate.
Pro Tip: If Microsoft Word inserts an opening quotation mark (‘) instead of a curly apostrophe (’) before a decade written as an abbreviated numeral (the ’20s), use the Symbol dialog box to insert a right single quotation mark, which is a curly apostrophe.
The right single quotation mark is located in the Symbol dialog box’s Symbols tab under the General Punctuation subset. Visit the following tutorials for more information on the Symbol dialog box:
If you’re looking for more information on formatting time periods, take a minute—or two—to visit these related posts:
1. The Associated Press Stylebook 2019 (New York: Associated Press, 2019), 81.
2. The Chicago Manual of Style, 17th ed. (Chicago: University of Chicago Press, 2017), 9.33.
3. The Chicago Manual of Style, 17th ed. (Chicago: University of Chicago Press, 2017), 9.33.
4. Publication Manual of the American Psychological Association, 7th ed. (Washington, DC: American Psychological Association, 2020), 6.32, 6.39.
5. The Chicago Manual of Style, 17th ed. (Chicago: University of Chicago Press, 2017), 9.33.