If you read the preceding set of numbers and slashes as June 8, 2015, then you are, without a doubt, as American as baseball, apple pie, and Britney Spears. But that would put you in the minority of the world’s timekeepers, as what Americans consider a standard date format is anything but.

The map above depicts the national date format standards for all countries that actually have these standards in place. As you can see, most of the world uses the metric system, which renders dates differently—today would be 08/06/2015. In China, it would be 2015/06/08 and in some places, like India, you could toggle between 06/08/2015 and 2015/06/08.

But even more than the U.S., there is one country whose date-keeping stands out: Canada. Canada accepts all types of date formats. From Prince Edward Island to Vancouver—you can pretty much write the date however you like. No holds barred. This obviously raises questions: how does this make sense? Do people really have no standard way of noting the days? Is this even legal?

The problem with date notation is that there really isn’t a right or wrong way to do it. Taken on its own, mm/dd/yyyy is just as effective at communicating the intended message–the date–in the same way that dd/mm/yyyy is. However, agreeing on a notation matters for things like vacation planning, bank transfers and missile launches.

Enter endianness. And the International Standards Organization. And the “Age of Maximum Confusion.”

Endianness is the sequencing of bytes of digital data in computer memory. The term comes from Jonathan Swift’s famous work, Gulliver’s Travels. In the story, a society is divided on the lines of where they break their eggs. Those that use the big end are known as the Big-Endians, and vice-versa. While the matter may seem quite unimportant, it resulted in a civil war between the two sides, and the needless deaths of good people.

To computer scientists, endianness is a system where the units are ordered based on size. It’s a way of explaining how you are storing computer memory—a big-endian system keeps the most important bit of information in the smallest address, a little-endian would do the reverse. As you can see on the map, most of the world, and some Canadians (whenever they feel like it) use the “little-endian” notation system – that is, dd/mm/yyyy. So 08/06/2015 would be today’s date. Only Americans abide by the “middle-endian” system, making today’s date 06/08/2015.

In a prescient 1980 paper entitled, “On Holy Wars and a Plea for Peace,” famed computer engineer Danny Cohen writes (on endian-ness and dates), “We agree that the difference between sending eggs with the little- or the big-end first is trivial, but we insist that everyone must do it in the same way, to avoid anarchy. Since the difference is trivial we may choose either way, but a decision must be made.” To computer scientists, and people who think about the date too much, imprecision begets confusion, and confusion begets anarchy.

Nonstandard date notation was behind Y2K fears (that people had been using the last two digits of a year instead of the full four in programming, and computers would go haywire). And post-Y2K, mathematicians have continued to sound the alarm about the lack of agreed-upon global instructions. As retired researcher Jim V. Blowers writes on his blog, we live in the “age of maximum confusion”:

“Now not only the month and day can be confused with each other, but so also can the year. 07/04/01 could represent a date in 2001 or 2007, or maybe even 2004. The digits 01 for 2001 can be confused with either the month or the day. This was the case starting in 2001. In 2000, it is obvious what 00 means. It will be like this until 2012, a period that I call the Age of Great Confusion. Because of the problem I mentioned above with ‘10 March’, the problem will be especially severe from 2010-2012, a period I call the Age of Maximum Confusion.”

It’s not like people hadn’t been trying to solve this problem in the past, though. In 1988. the International Standards Organization (ISO) came up with a 33-page document describing a standard called “ISO 860”, that states that the international standard for dates is yyyy-mm-dd. From 1988 onwards, all international bank transfers were done with ISO 8601 international dates. Though this is largely due to the demands of ubiquitous technology, it’s still a huge victory for the Big-Endians.

So where does this leave Canada? Still in chaos. According to a spokesperson from the Canadian Payments Association, all formats for reporting the date are equally acceptable – no matter if you choose to write the day, month, or year first. However, all Canadian checks have date field indicators, which must be filled out prior to deposit or else the bank will not accept the payment. The spokesperson said this convoluted policy resulted from a consultation with stakeholders in 1997, where people were so opinionated that no consensus could be reached. (The spokesperson did say that ISO 8601 dates are the preferred format, and the Standards Council of Canada recommends it.*)

In 2011, Ontario MP Daryl Kramp introduced a bill that sought to bring use the ISO 8601 date system in all Canadian legal proceedings.* While this is a great move for the cause of Canadian date uniformity, change happens slowly. For now, as a Canadian, I’ll be baffled by the date until 2031, when the years, months, and days can finally no longer be confused.

* Updated: This story was updated on December 4, 2018, to clarify that the Standards Council of Canada recommends ISO 8601, and that Kramp’s bill was to standardize date format in legal documents.

Map Monday highlights interesting and unusual cartographic pursuits from around the world and through time. Read more Map Monday posts.