Campaign to get the Internet World to use the 
International Date Format

Ever been to a page to see that the press release you are interested is dated 04/05/96?

Is this date the 4th of May 1996 or the 5th of April 1996, and presumably, the 96 refers to 1996?? In order to make the right choice, you must ask yourself some questions : Which one is it? It could be very important to you.

The Internet is a truely International method of communicating - there are no political or cultural boundaries drawn on the www page you call up - the page could have been stored in the Smithsonian Institute or on a small server in a basement in Ulan Bator, Mongolia. Often, you have no way of telling. So, if anyone in the world can read your page, why not ensure that any date references on that page can be read correctly and unambiguously by that person, by using the ISO 8601:1988 International Date Format.

Imaginary scenario

It is AD 4312 and 7 year old Jasorra Smith is asking his mother about the ancient days....

"When was Cold Fusion invented, mummy? It says in my history book it was in 11/07/02? Was does that funny number mean?"

"Well, Jas. Even though it was an amazing discovery that we use every day to power our homes, androids and space transporters, no one is quite sure what date this number actually refers to. During Global War 5, much data from the old world was lost. In those ancient days there was no universal date standard like we use now, and every country seemed to write the dates in different ways. The historians say it is probably the 11th of July 3002 but the Space Band say it is not a date at all, but a magic code to help unlock the mysteries of the universe. The Church of the Fifth Coming say it is the sign of the devil. But the truth is, they are all guessing.... if only they had listened to Steve.......

So what is this date format?

CCYY-MM-DD

where CC is the century, YY is the year, MM is the month of the year between 01 (January) and 12 (December), and DD is the day of the month between 01 and 28 or 29 or 30 or 31, depending on length of month and whether it is a leap year.  These dates are using the Gregorian calendar.

For example : 1998-01-15 is the fifteenth of January in the year nineteen ninetyeight A.D. - completely unambiguous

Simple, isn't it?

Eleven good reasons to use it

Note 1 : there are several calendars in use around the world using different reference points (eg. AD 1996 in the Jewish calendar is 5757, in the Islamic calendar 1417) but whenever any of the people using a local calendar speak to anyone outside their calendar regime, they use the Gregorian calendar, so this can be considered to be the international standard for year representation.
A bucket full of stuff on calendars is available elsewhere.

Let's be sensible...

Despite my campaign, I would not expect anyone to talk about dates in a numeric way - "Did I tell you about our new arrival? He was born on nineteen ninety-five, zero nine, zero five, just before tea" - not very flowing is it? Within a document, date notations like 7th October 1996 or October 7th 1996 or other unambiguous formats can be used.  However, 05/06/96 style formats should be avoided at all times.

The International Date Format is for time-stamping of data so that anyone in the world, of any nationality will know, without ambiguity, which date the information relates to. For example : press releases, scientific papers, legal documents, any time-stamped data, important events in the future or past.

Download your own, full, unabridged version of the standard :

ISO 8601 : 1988 (E) Data elements and interchange formats – Information interchange – Representation of dates and times
 

Other related links of interest:

International Organisation for Standardisation
Date formats
Ian Galpin's Page
Marcus Kuhn's page
Japanese Association of Translators

World Representatives of this campaign
 
Contact your local rep :
 
Country Representative Email address
 
United  Kingdom Steve Adams steve@saqqara.demon.co.uk
Canada Deborah Wright preproof@ii.ca
U.S.A. Paul Devalier pdevalier@hellerfin.com
Sweden Ulf Jordan e4jordan@etek.chalmers.se
Uganda Sam Waniala megmicro@infocom.co.ug
Your country here Your name here Your email address here
If you want to be your country's rep for this campaign then email me and I'll add you to the list

What about time representation?

Fortunately, the ISO 8601 standard covers this too.

A very large percentage of the world uses the 24 hour time format so they have no major problems.  One notable exception is the USA (but they still use Fahrenheit for temperatures, so it's no wonder!).  Hopefully they will see sense in the near future...

A great example of an undefined time using the a.m./p.m. type of time is 12:00 a.m.  Is that midnight or midday??  As with the dates, getting the correct interpretation of this value could be crucial.

ISO 8601 comes to the rescue....

00:00 is midnight and 12:00 is midday - simple

... and before you query this, 24:00 is also midnight and is the same instant in time as 00:00.  It just indicates the end of a day instead of a beginning.
 

The unambiguous date and time formats have been defined - please use them

Page last updated 1998-11-31
Return to HomepageEmail Steve