The 1920s, the ’20s, the twenties: writing dates

Penny at podium_croppedA few months ago, we agreed that apostrophes do not belong in plurals: To make a plural, generally you add an s or es. No apostrophe. The same rule applies when you are referring to a decade, say, the 1920s. It is absolutely fine to put a letter after a number without an apostrophe between.

If, however, you decide to drop the 19 from 1920s, you would insert an apostrophe to show that something is missing: the ’20s. (After all, that is one of the apostrophe’s jobs: to show that something has been removed.)

You could also spell out the abbreviated form as “the twenties,” keeping it lower case unless you are talking about the Roaring Twenties, a distinct historic era. The Chicago Manual of Style,[1] NEHGS’s style guide of choice, says, “Decades are either spelled out (as long as the century is clear) and lowercased or expressed in numerals.” I’ll repeat: As long as the century is clear. In genealogical writing, we’re often discussing such long spans of time, and precision is so essential, that we will probably always want to use the form 1920s, to distinguish the twenties decade from the 1820s or the 1720s or the 1620s—and soon from the 2020s.

Here are some other basic guidelines for writing dates:


When discussing the century, spell the ordinal number:

 seventeenth century; twenty-first century

When using the century as an adjective preceding a noun, use a hyphen between the number and the word century:

 seventeenth-century artifacts; eighteenth-century migration patterns; twenty-first-century fashions

Specific dates

In genealogical writing, it’s common to use the day-month-year style, which requires no comma:

 10 April 1909

If you are writing narrative text and choose to use the month-day-year style, place a comma between the day and the year—and also after the year if it does not end the sentence:

My father was born April 10, 1909, at the family home in Bellaire, Ohio.

If you are giving only the month and the year, or a holiday and a year, you do not need a comma:

 April 1909; Thanksgiving 2014

Regardless of how specific dates are pronounced in speech, use cardinal numbers when writing dates:

 April 10, 2015 (not April 10th)

Exception: It is fine to use ordinal numbers in Quaker dates:

3 1st month 1653

Range of years and double dating

When expressing a range of years with a dash between the years, pick one of two styles: the full-number style, giving each numeral, or the abbreviated style. Be consistent!

 Full-number style: 1894–1895; 1900–1901

 Abbreviated style: 1894–95 but 1900–1; 1899–1901

When expressing double dates (necessitated by the switch from the Julian to the Gregorian calendar; see “Double-dating”), use a slash between the years, and use either the final digit of the second year or the final two digits. Again, be consistent!

 1715/6; 1722/3


 1715/16; 1722/23 but 1700/1 (not 1700/01)

Do you have questions about how to write dates? Would you like to see posts on similar topics? Add a comment with your questions or suggestions, and I’ll try to address them in future posts.


[1]The Chicago Manual of Style, 16th ed. (Chicago: University of Chicago Press, 2010), 476.

About Penny Stratton

A veteran of the book publishing industry, Penny Stratton retired as NEHGS Publishing Director in June 2016; she continues to consult with the Society on publications projects. Among the more than 65 titles she managed at NEHGS are The Great Migration Directory, Elements of Genealogical Analysis, Genealogist’s Handbook for New England Research, and the award-winning Descendants of Judge John Lowell of Newburyport, Massachusetts. She has written for American Ancestors magazine and is a regular poster on Vita Brevis. With Henry B. Hoff, Penny is coauthor of Guide to Genealogical Writing: How to Write and Publish Your Family History; she is also the author of several Portable Genealogists on writing and publishing topics.

20 thoughts on “The 1920s, the ’20s, the twenties: writing dates

  1. I have read so many of the Paston letters, I actually today when writing personal notes, use e.g.,

    4th day of April, 2015

    To-date, none of my recipients have commented on it. LOL

  2. I, too, was brought up with The Chicago Manual of Style, and use it a lot! One thing I find tedious is finding and using pronouns, or synonyms, to replace proper names. Sometimes when I finish up a certain family story, I find I’ve used the same name or word way too many times! For instance, when starting the next paragraph, is it proper to use a pronoun?

  3. Penny – I am confused. You wrote. “1715/16; 1722/23 but 1700/1 (not 1700/01).” Why not 1700/01 if you have been using two digits throughout? As you said, shouldn’t we be consistent.
    And a belated thank you for the plural blog. I have been waving it at various people .

  4. Hi, Howland–Generally the zero is dropped from a continued number. You know, I’m not sure why–except that’s what Chicago Manual of Style specifies, and thus it’s what I have done ever since, say, the 12th edition or whatever was the latest version of CMS when I began working in publishing.

    I am still smiling at the vision of you waving the plural blog in front of people!

  5. Tangentially related: My wife is from Russia, and they have what I consider a rather elegant way of expressing dates — it is day, month, year format as we use in genealogy, but the month is expressed in Roman numerals rather than words. For example, (Western) Christmas Day this year would be 25 XII 2015. It makes for impressive monuments.

  6. So – when pluralizing a surname with ‘es’ drop the ‘e’ and use an apostrophe as in “..tes’s ” as opposed to “..teses ” which is cumbersome ???

    1. Maj, I agree that “…teses” is cumbersome–but you should not use an apostrophe to form a plural. The plural of Bates, for example, would be Bateses. If it were me, I’d reword the sentence and say something like “the Bates family.”

  7. I’m almost 70, but I love this review of Miss Tyndall’s freshman English class. But then again, I loved English!!!

  8. Penny, in a related note, recently I was astonished to see an experienced genealogist refer to the “16th century” when he was referring to the 1600s. I’m sure it was an inadvertent error, but it was a good reminder to me to double-check how I label centuries! Perhaps a column on this convention as well?

  9. Wonderful post. But we also have to remember to always spell it out in our research – whether writing or talking. To use ’20s will soon confuse with 2020. Maybe we need to be consistent from now on and always use the full date? I always do whether typing a letter or hand writing a letter…today would be 30 April 2015. I never use 4-30-15. Not even when dating my signature.

  10. I am somewhat surprised! I had not idea that “A few months ago, we agreed that apostrophes do not belong in plurals: To make a plural, generally you add an s or es. No apostrophe.”

    I have always, for example, written Bates’. Have I always been wrong? Or has this, indeed, been a recent modification of rules? Who agreed to this a few months ago?

    Thank you, Penny! This is why I do subscribe to a number of genealogical blogs. It is always surprising – if not alarming – how mis-informed one can be! It is good to be correctly late rather than not at all!

    1. This rule on the plural of someone’s surname has not changed. If you are Jones, then your family of 2 or more is Joneses, Williams becomes Williames. Now, you do use an ‘s to show possession or ownership. John Jones’s house or it can be expressed as John Jones’ house, but if you include his family in the ownership, it would be the Joneses’ house or Joneses’s house. I learned to add ‘s after the plural of a surname, but the rule has changed in recent years to say that one can drop the s after the apostrophe. I think like many people you have confused plurals (adding s or es) with possessives/ownership where you add ‘s or just ‘.

  11. Objection!! (And, yes, I have CSM 14 on the shelf to my right side).

    You wrote: “…[he] was born April 10, 1909, at the family home….” as an example of placing a comma AFTER a date but before a letter when writing out the date in that format.

    Now, I can see why a comma NEEDS to be placed between 10 and 1909. It is a VISUAL demarcation. In effect, it stands in for the spoken “th”, as we say “April Tenth 1909”, rather than “Ten”.

    But AFTER 1909? Such a comma doesn’t stand for any verbal pause if said statement is spoken alive. And, visually, it interrupts the flow of actually reading it. And, logically, the use of that comma should necessitate a prior comma, so that the date is itself set off as subordinate to the main meaning of the sentence: “…[he] was born, April 10, 1909, at the family home….” If you take the date out but leave the comma it looks like this: “…[he] was born , at the family home….” which is absurd whether read or spoken. Why the inclusion of a year date would make it OK is beyond me.

    In my view, a comma after a year date is now an Affectation of Style, similar to how early nineteenth century writers, e.g. Emerson throughout “Nature”, would place a space BEFORE commas, semi-colons, and colons. The space emphasized the pause suggested by the punctuation, I guess ; it disappeared from reprints even before RWE died.

    I note that there seems to be no need for a comma after, say, “10 April 1909”. Yet, it would seem to me the same reasoning (whatever that might be) regarding the given example ought to apply to that date format, too.

    Returning the soap box to you.

    1. A punctuation aside, but interesting if researching French ancestors –
      In French a space always precedes a punctuation mark that contains 2 elements such as ; : ? or !
      There is not preceding space for one-element punctuation such as ) . [

  12. If an author insists on spelling out the year, is it correct, using “the 1920s” as an example, to write, “the nineteen twenties,” or “the nineteen-twenties”?

    1. Hi, David–

      Chicago Manual of Style, which I use as my Bible, calls for using numerals for dates. If the author insists on spelling them out, use “the nineteen twenties”–or, if the century is clear from context, “the twenties.”

  13. What is the proper way to abbreviate 1969: ’69, or ‘69 (notice the close and open apostrophe)? My word processor types ‘69 and then auto-adjusts to ’69.

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