Dates

The Brits and most of the rest of the world write their dates in day-month-year (DMY) format, e.g. 18-05-2029. Americans use MDY, e.g. 05-18-2029. People argue about which is more logical.

When we write a number, we write the most stable digit first. 5 hundreds, 3 tens and 1 is written 531, not 135 or 315.

When counting from 100 to 999, the last digit changes frequently, the second digit changes once every time the last digit has changed ten times, and the first digit changes once for every time the second digit changes ten times. It’s the most stable.

It would be logical to do the same thing with dates. The part that changes least often, the thousands of years should be written first, followed by the hundreds of years, then the tens of years, then the years, then the tens of months, then the months, then the tens of day, then the days, e.g. 2029-05-18.

If we included the time, this should follow on in the same manner, hours first etc. For instance 2029-05-18T14:31:40.

Adding in the time zone, we get 2029-05-18T14:31:40+06:00.

This is Standard ISO 8601 of the International Organization for Standardization.

A big advantage of this date format (apart from the fact that it’s just logical) is that when sorted alphanumerically, the dates end up in chronological order. British dates end up with the first of any month and any year all clustered at the start, followed by all the seconds-of-the-months, and so on. The American system isn’t much better. There are 9 countries which use the YMD format exclusively. They are China, Japan, Mongolia, North Korea, South Korea, Taiwan, Bhutan, Hungary and Lithuania. See the map below.

Yellow: YMD Blue: DMY Red: MDY Pink, brown: varied formats

In addition, many other countries will use the YMD format in some situations and other formats in other situations. The YMD format is, in those countries, a recent innovation which makes things much easier when computers are involved. It would seem likely that the YMD will gradually take over from other formats. The map shows that YMD is an accepted format alongside the traditional format in many of the world’s countries, particularly those where technology is more advanced.

I always use the YMD format and, if others do the same, everyone will eventually get used to it.