Microsoft Loves Regional Date Formats but Hates “Colour” and “Honour”

The whole point of formats is for communication: having a separate Afrikaans date format defeats the purpose

Every time you set up a fresh Windows installation, Microsoft asks what region you’re in, then configures your system to display dates, times, currencies, and number formats according to the precise conventions of your corner of the world. Within English alone, there are dozens of country-specific locale options, from English (Belize) to English (Trinidad and Tobago) to English (Zimbabwe), each carrying its own permutation of whether the month or day comes first, whether a comma or period marks the decimal, and whether noon is 12:00 PM or just 12:00.

Meanwhile, ISO 8601 has specified YYYY-MM-DD since 1988, a format that is unambiguous, sortable, and universally parseable, and the 24-hour clock eliminates the absurdity of wondering whether “12 PM” is noon or midnight. But default settings on consumer operating systems keep the general public from adopting them.

Open a fresh Excel spreadsheet and type a date, and Excel will format it according to your locale: an American sees 3/22/2026, a Brit sees 22/03/2026. Send that spreadsheet to a colleague in another country and the silent corruption begins, because nobody can tell whether 04/05/2026 refers to the fourth of May or the fifth of April. This is a machine for generating ambiguity at planetary scale, and it ships as the default configuration of the world’s most widely used data tool.

Microsoft forces American spelling on all of us

Strangely, with spelling Microsoft has the opposite approach: open Word in Canada, Australia, or the United Kingdom, and you will spend your first twenty minutes fighting a spellchecker that insists “colour” should be “color,” that “organisation” needs a z, and that “centre” is a typo. The default English across Microsoft’s ecosystem is American English, and switching it is a multi-step process that most users never bother with.

So for some reason, for spelling, Microsoft imposes a single American standard and makes you work to change it. For *date and time formats*, where an actual ratified international standard exists that would eliminate real confusion, Microsoft instead celebrates every regional quirk and makes you work to escape it.

Google behaves identically. Google Sheets inherits your locale settings, Google Calendar formats times based on where it thinks you are, and the 24-hour clock, which is used by most of the world’s population and the entirety of its transportation and military infrastructure, remains opt-in across virtually every Google product.

Defaults Are What Matter

The usual defence (or “defense”, as Chrome insists to me as I write this) is that users can change their settings, but research on default effects, from organ donation opt-in rates to cookie consent banners, consistently shows that the vast majority never do. Tech companies know this better than anyone, since it is the entire basis of their design philosophy for everything from privacy settings to notification preferences.

When Microsoft and Google default to MM/DD/YYYY in the United States and DD/MM/YYYY in Europe, they are perpetuating an interoperability disaster that costs real time, real money, and in fields like medicine and engineering, poses genuine safety risks. They preserve ambiguity because the ambiguous option feels familiar, and familiar defaults generate fewer support tickets.

Webster Did It With a Dictionary

The reason Americans write “color” instead of “colour” is that Noah Webster decided they should. In the early 19th century, one man with a dictionary and strong opinions about how English ought to look managed to permanently fork the spelling of an entire language. He simply published his dictionary with the spellings he preferred, the American school system adopted it, and within a generation the changes were irreversible, all because one person chose a default for an entire continent.

Noah Webster: Opinionated about spelling, he permanently split the English language

Microsoft and Google now have more influence over how humans read and write dates than Webster ever had over spelling, since their software touches billions of people daily. The difference is that Webster actually used his position to impose what he believed was better. Microsoft and Google have the same leverage and do nothing with it, or rather, they actively engineer the perpetuation of dozens of incompatible regional formats that nobody chose deliberately and everyone suffers from. They could ship ISO 8601 as the default tomorrow. Spreadsheets could store and export dates in that format unless the user explicitly opts out. The 24-hour clock could be default, with 12-hour time available as a preference.

Even decimal separators and thousands separators deserve to be opt-out standardized, since a world where 1.000 means one thousand in Germany and one point zero zero zero in the United States is a world designed for misunderstanding, and the confusion only compounds when these numbers appear in spreadsheets and financial documents that cross borders daily. The ordering of year, month, and day, the notation of time, the formatting of numbers: all of these arbitrary things should converge to standard answers, and two of the most powerful software companies on Earth have chosen, with enormous engineering effort, to perpetuate a diversity of possibilities.