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 :
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Is the site you are visiting in the U.S.A.?
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Is the site in a country which supports the U.S.A. style date format (mm/dd/yy)?
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Which countries do officially use the U.S.A. style date format?
Is there an official list?
-
Is the page author
-
an American?
-
someone who thinks or wishes he/she was?
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an American living in a foreign country?
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a foreigner living in America?
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someone using this format because they think it is standard?
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confused, and has simply got the first two numeric fields the wrong way
round?
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
-
language independent - a true international standard from the International
Organisation for Standardisation (see Note 1)
-
cannot be confused with any other popular date notations
-
consistency with the common time notation system, where the larger
unit (hour) is written in front of the smaller ones (minutes and seconds)
-
easily readable and writeable by software (no month name to number
conversion necessary)
-
easily comparable and sortable with a trivial string comparison
-
strings containing a date followed by a time are also easily comparable
and sortable e.g. 1996-01-15 22:45:37 with most significant value to
the left
-
the notation is short and has constant length, which makes both
keyboard data entry and table layout easier
-
identical to the Chinese date notation, so the largest cultural group
(>25%) on this planet is already familiar with it - so no feeble excuses
like "but no-one uses this format..."
-
date notations with the order "year, month, day" are in already widely
used in Japan, Korea, Hungary, Sweden, Finland, Denmark to name a few.
Even people in the US are already used to at least the "month, day"
ordering
-
a 4-digit year representation avoids the Year
2000 problem. If only they had thought of that when computer
technology was being developed...
-
Astronomers have been using this format for centuries
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 |
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
