Alternatively: why and when did others switch away from MM/DD/YY, if they ever used it?

I always write out the month name to avoid ambiguity.

Update: Since it came up in the comments, I'm asking about humans, not computers.

Note: There's already a question which includes this, but the answers focused on the metric system. The normal reason for the US hanging onto the Imperial measurement system, an install base untouched by WWII, don't seem to apply to a date format.

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    Actually, my answer there was exclusively on the date system. If I were to answer this question, it would be a substantially identical answer. – T.E.D. May 16 '16 at 20:37
  • In prose a date is written May 16th, 2016, the same order as MM/DD/YY. – Tyler Durden May 16 '16 at 20:43
  • @TylerDurden - Well, you could swap the month and date by throwing an "of" in there. Then you could argue that's more awkward, which is in fact what you'd find my answer to the previous question doing. – T.E.D. May 16 '16 at 20:46
  • @T.E.D. I saw your answer, but I found it speculative. Maybe you could provide a focused answer with sources to back up the idea that DD/MM/YY works better in French (and presumably other European languages) and that the US didn't change because they only have to worry about English? Alternatively, you could cover the flip-side of the question: what was everyone else using and why did they change? – Schwern May 16 '16 at 21:21
  • Comments are not for extended discussion; this conversation has been moved to chat. – T.E.D. May 19 '16 at 13:49

The US Army had standardized dates as Month day, year by the War of 1812; I've recently been going through record books, and the clerks are consistent. Federal records published during the 1830s are consistently in this format. For example, see the records of Prize Money awarded for the Battle of Lake Erie, as published in American State Papers: Documents, Legislative and Executive, etc. series 23, 1834.

Older documents, and British records, are mostly Day-month-year, which makes the US Army and the Federal Government the innovator.

OTOH, Civil records are mostly DD-Month-YYYY "this day Detroit, 7th February, 1813.", and continue this way into the 1830's, where both systems are found in court records, receipts, and family bibles. You can see the change occuring in family registers. enter image description here

By the late 1840s, at least in Michigan, most records, federal, local, and personal, have gone to the Month day, year format. You also see the decline and disappearance of the long s from the script.

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  • "Older documents, and British records, are mostly Day-month-year, which makes the US Army and the Federal Government the innovator." Not quite. Lord Chesterfield's Letters to His Son (1740s) are dated month, day, year. – TheHonRose May 17 '16 at 21:55
  • This does not answer the question "why?" The rest of the world writes day/month/year, which seems to be more logical. – Alex May 17 '16 at 22:04
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    One can never answer "why" questions; only how it came to be. In this case, it was the adoption of this standard by the US government which appears to have influenced common habit, until the older method had essentially disappeared by 1850, if not earlier. The adoption of a standard protocol by a government agency has little to do with so-called logic, which is often retrodictive in nature. – Peter Diehr May 17 '16 at 23:40
  • Maybe the early US military wanted to confuse the British enemies so they are never sure if that date they are reading in a confidential US message is in DDMM or MMDD. – Acroneos May 18 '16 at 22:06

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