Date formats

Matthias Paul posted this information to the FreeDOS mailing list about date formats, which I am reproducing here:

Yes, the date format specified by DIN EN 28601 (approved in 02/1993) ([cc]yy-mm-dd) is mandantory in German offices since May 1996 (although most people still donīt know of the change... ;-)

Expressively, the traditional date format[cc]yy is no longer valid, but still used by the vast majority. Only verbatim forms like "11. Februar 2001" are still allowed in the old format.

For those interested, we just had a very detailed discussion of the various date & time format issues in different countries and the EN 28601 & ISO 8601 international standard in particular in the 4DOS BETA forum.

Hereīs a link to some background info on the ISO 8601:1988 standard (includes a .PDF version of the actual standard and many links). Some may also find my JPDATE49.ZIP package useful to patch their existing COUNTRY.SYS files (itīs freely available on my homepage and other sites) and new significantly enhanced issues of my COUNTRY.ZIP and CPI.ZIP packages are available on email request (until I find the time to tidy them up and upload).

BTW. DR-DOS 7.02 introduced new country codes in the range 10000..31999. These are sets of alternative country codes, e.g. 20nnn supports the ISO date format, 21nnn supports the Euro currency, 22nnn is to support the ISO & Euro, 30nnn is reserved for user definable country codes (NLSFUNC 4.01+ supports the use of multiple COUNTRY.SYS files at the same time (even mixing MS-DOS and DR-DOS style files) and access them as a combining NLS database, which can be distributed over various locations on disk or network), and 31nnn is reserved for OEM definable codes (whereby nnn corresponds to the traditional country code). There are some exceptions of the rule, and not all combinations are valid for all countries. Codes in the 2mnnn range should report *this* code back to the system, while alternative codes in the 1mnnn range may return the old nnn code to the system (but NLSFUNC should better not be loaded then). This is because some old applications get confused by country codes above 999. The old codes nnn still report the old country data for backward compatibility purposes.

The idea is that a simple "modulo 1000" can be used to fold a country code in the range 10000..31999 (and only in this range!) back into 1..999, for example to continue to use old source code when determining the language of messages or other hard-wired country dependent issues, that do not otherwise take these enhancements into account. Country codes in the range 1000..9999 and 32000..65534 are reserved for future use and must not be included in the modulo operation! Country codes 0 and 65535 are reserved by the system itself.

An example: COUNTRY=20049 is the new country setting for Germany, similar to the old one, but now with the DIN EN 28601 date format. In case this would cause problems with applications, one should use the 10049 code instead. If one still wants to use the old country data, itīs still available under country code 49.

Ian Galpin (new Editor for the ISO 8601 Standard section of the Open Directory Project (ODP)) adds:

It would be wise to point out that this is only the German implementation of EN 28601; and that the EN 28601 standard is the pan-European implementation of the ISO 8601 world standard. This may help people look up their own local implementation.


This site [ISO 8601:1988 First Edition, above] still contains the summary, but no longer has any links to PDF copies of the standard. The old link was to the ISO 8601:1988 First Edition, but now this link no longer works.

The ISO 8601:1988 standard can now be found at: 8601.pdf and iso8601.pdf.

The 2000-12-15 Draft Version of ISO 8601:2000 is at: pdf00005.pdf, 154n362.pdf.

The ISO 8601:2000 standard now refers to 'YYYY-MM-DD' rather than the 'CCYY-MM-DD' terminology used in the ISO 8601:1988 standard. With 'CCYY' a year of 1950 had a 'Century' of '19' and a 'Year' of '50', even though 1950 is clearly in the 20th Century. ISO were heavily criticised for this, hence the change in the new edition of the standard. Perhaps you could make mention of this in your texts. The new standard, ISO 8601:2000 refers to 'YYYY-MM-DD' instead.


You often use a long date format such as: 'December 07, 1998' in your various texts. Now that Year-Month-Day, and ISO 8601 thinking is becoming more common, a lot of people are now writing dates like '1998-12-07' or '1998-Dec-07', or '1998 December 07'. I definitely recommend this.

The ISO standard only deals with numeric dates, but ISO have still used the Year-Month-Day order in many of the worded examples within the 2000 version of the standard.

There are many people who already do this. The NASA Web Site located at web site has been doing this for very many years, writing all dates in the Year-Month-Day order, whether numeric or not.

The IBM Year 2000 Book also used the Year-Month-Day ordering, even in long format dates, to good effect.

The search engine located at: uses the '2001 Feb 03' date format when returning results. They use this as a staging point to get people used to the Year-Month-Day ordering, before taking the big leap into a fully numeric format at some later date. In all cases, they already use the full four digit year representation.

There are now very many sites that deal with ISO 8601 and related issues. Quite a few of these are now collected together on the ODP web site mentioned above. If you have space, perhaps you could consider putting a few more links back to the ODP web site, some of the other sites that are listed on there, and any other ISO 8601 references that you can.

Here are a few other sites that you may wish to consider:

  1. Discussion About the ISO 8601 Standard (YahooGroups).
  2. Implementation of the ISO 8601 Standard around the world - a list of countries around the world that have adopted the ISO 8601 standard.
  3. ISO 8601 Dates: What They Are and Why They're Good - University of Illinois at Chicago in USA:
  4. Using the ISO Date Format on Personal Computers
  5. Date and Time - Week Numbers - by Peter J Haas in Germany.
  6. Date and Time on the Internet - Timestamps - Chris Newman.
  7. International Standard Date and Time Notation - by Markus Kuhn.
  8. Info on ISO 8601, the date and time representation standard.
  9. Setting up your PC to use the Year-Month-Day date format.
  10. Setting up your Mac to use the Year-Month-Day date format.
  11. International Date Format Campaign - by Steve Adams.
  12. ISO 8601 Date and Time - Converting and Implementing.
  13. ISO 8601 Date/Time Representations - A simple introduction to ISO 8601 date and time formats - University of Wellington in New Zealand [This is one of the 'original' ISO 8601 documents, one of the very first web sites that ever mentioned the standard].
  14. Discussion of formats for expressing dates, with particular reference to the ISO 8601 date format - by Peter Meyer.
  15. W3C Date and Time Formats - A Note concerning usage of ISO 8601 on the Internet - by Misha Wolf and Charles Wicksteed.
  16. ISO Date/Time Formats
  17. Standards for Representing Dates - University of California at Berkeley.

There are various draft copies of the ISO 8601 standard available on the net. There is a web page that has links to many of these. This is located at: