The Question of Writing Dates

by , under How To, Online Research

In an online article “Data Entry Standards for Genealogists & Research,” there is a section on Dates. Here is what this guide says about entering dates:

  • The most readable and reliable format for presenting dates is day, month, year; this style is least likely to create confusion when entering, matching, or merging data.
  • Abbreviate months as: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec without a period. Enter days with double digits and present four digits for the year.
  • Dates can be estimated, if documented as such, by preceding the date with one of the following codes which are all entered without a period: about = “abt” after =“aft” before =“bef” between =“bet” calculated =“cal”

Go here to read the entire article:

I bring this up because I still see many date entries in online family trees using the practice common in American English of entering a date in all numerals with the month, day, and year separated by slashes. Thus, the 4th of July 2000 would be written 4/7/2000. The Cambridge Dictionary Online website uses this specific example to illustrate how American English differs from British practice, pointing out that the date would be 4/7/2000 in British English.

The practice in genealogy outlined in the article above is preferred because it spells out a date precisely. The reader will not misunderstand the day of the month or the month. Also, there is no confusion about what century is referred to, as in 1916 or 2016, which there possibly could be with the year presented only with two digits as 16.

I find that I am so conditioned to using the genealogical approach to writing out dates that I date my handwritten checks (I still use these for some payments) in the format two-digit day, three-character month, and four-digit year.

I do use another format whenever I am entering dates into my Evernote application on all my devices, which sorts everything automatically and will find anything I want to retrieve. It is the ISO style for dates. Here is how the Chicago Manual of Style describes it:

The International Organization for Standardization (ISO) recommends an all-numeral style consisting of year-month-day (i.e., from largest component to smallest), hyphenated. The year is given in full, and the month or day, if one digit only, is preceded by a zero. Thus January 19, 2010, appears as 2010-01-19. Among other advantages, this style allows dates to be sorted correctly in an electronic spreadsheet and other applications.

This is found in the Chicago Manual of Style online at

Again, this is the date entry style I use for notes in Evernote. Each note with a date in the title is filed chronologically, either in ascending order or descending order, depending on my setting at the moment for sorting for the database.

For further reading on dates in genealogy:

MyHeritage Blog pont of 12 Jan 2015 entitled “Understanding Dates: Five common mistakes to avoid” at

“Introduction to Genealogy, Lesson 1e: Recording Dates” is a comprehensive article about the subject at Genealogy. Go here:



  1. Jeremiah Edwards

    How would you write 03 Aug 1879? Is it correct to use a 03 or a 3 for the day?

    • whuskonen

      Technically, either is OK, but 03 is more consistent with other dates of 10 or greater.


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