Date format in UK vs US

Although there are people who will sometimes say:

1. Today is Thursday, the 24^th of May, 2012.

There are also others who instead say the same thing this way:

2. Today is Thursday, May 24^th, 2012.

Certainly in the United States, the second way of mentioning a date is more common than the first. The long form sounds more formal to us, as in “on the Fourth of July” being more formal and long-winded than simply saying “on July 4^th”.

It was pronouncing the month before the day out loud that gave to retaining that same original order when converted to digits: merely convert the month name to a natural number, and there you have your answer. What’s today’s date? It’s May 24^th. Instead of writing May-24, we simply change the “May” to “5” and write 5-24 or ⁵⁄₂₄.

That way it follows the natural language order and so requires no mental gymnastics to switch things around when speaking the date aloud. Similarly “September 11^th” gets written ⁹⁄₁₁, etc.

The full spoken form with the year, “May 24^th, 2012”, then becomes the written shorthand “5/24/2012”, or often just “5/24/12”. “Christmas of 2001” can be, and somewhat annoying often is, written “12/25/1”, while “January 25^th, 2012” becomes “1/25/12”.

This isn’t usually any sort of problem because of universal consensus on how to interpret such things in the United States. If you write day/month/year in America, you will not be understood. Although I myself prefer the ISO notation, normal people do not use it in their daily affairs.

It's very possible that the US inherited this from an outdated English format - much like the length unit, after Henry III's foot and which the English have left behind in favour of the more logical metric system.

One argument I've heard in favour of the American system of dating is that the numbers of months in a year is smaller than the number of days in a month which itself is smaller than the number of possible years. So you would have 12/31/2013, in ascending order. I don't really buy this argument, but OP might be interested in it anyway so here it is.

Meanwhile, in Northern Europe they've moved on to an opposite, descending date standard: year/month/day.