Author: Ian Galpin, G1SMD.    Original Date: 1998-Aug-08.

Page Revised and Posted to: <http://www.qsl.net/g1smd/isoeme.htm> on: 1998-Oct-22.

This Paper was Originally Presented at the 8th, 432 MHz and Above, EME Conference in Paris, France on 1998-Aug-08.

A Common Date/Time Standard for Amateur Radio.

  by Ian Galpin, G1SMD.

The representation of Dates, Times, and Time Zones has always caused much confusion around the world. This is especially true in an International activity such as Amateur Radio.

Radio Amateur operators now generally use the 24-hour clock system (rather than the 12-hour am/pm version) and the UTC time zone (rather than Local Time) for skeds, logging, QSL cards, band reports and so on. This helps in the International communication of such data, especially across language barriers.

The way that we write times is defined in an International Standard called ISO 8601. It calls for 24-hour clock, colon ':' separators, and the 'hh:mm:ss' ordering of the time elements. Imagine the chaos if some countries used 'ss:mm:hh' or 'mm:ss:hh' for times! What would a time like '10:08:04' then mean to different people around the world?

Now consider the situation with dates. The use of the 'dd/mm/yy' date format in some parts of Europe, and 'mm/dd/yy' in America has always caused confusion and ambiguity. A date like '04/08/02' means different things to different people (4th August in UK/Europe, April 8th in the US; in Japan it means August 2nd).

We are also hearing a lot about the so-called 'Year 2000 Problem', which is mainly caused by the use of a two-digit shorthand for the year, instead of using the full four digits. After the end of 1999, there may be confusion with computer programs and in all sorts of other date-related information.

In fixing the 'Year 2000 Problem' there is a good opportunity to deal with the other long-standing problems with date formats. Fortunately, a simple solution to all of these problems already exists in ISO 8601.

The date is written in the order Year-Month-Day. The year is written using four digits. The month and day are written in two-digit format, with a leading zero from '01' to '09'. Optional hyphen separators are used between the various elements.

The ISO format ensures that '2001-02-03' cannot be confused with '03/02/01', '02/03/01', '03/02/2001' or '02/03/2001' as variously written in some parts of Europe and in America.

Some people use the Year-Month-Day order but state the month using either a three-letter English abbreviation or written out in full. The month may even be written in your local language if there will be no problem for the intended readers to understand it.

For example, the new date format writes the date of the 1998 REF/DUBUS 432 MHz EME contest using any of the following fully interchangeable ways:

     19980308          (all digit, no separator)
     1998-03-08        (all digit, hyphen separator)
     1998-Mar-08       (short format for month)
     1998-March-08     (full name of month)

We are already using the ISO 8601 method for time. The proposal is simply to write our dates in the same logical way, with the largest units first: Year-Month-Day and then Hour:Minute:Second.

We all understand the time '22:44:59'. There should be no problem with a date like '2002-04-08', whereas a date like '08/04/02' has at least six different interpretations around the world.

The ISO 8601 date format has already been officially adopted by most countries of the world. In Europe, every member state is bound by the CEN regulations to implement EuroNorm EN 28601, which has the same wording as ISO 8601. In the USA see the ANSI X3.30 standard. The ANSI standard is also recommended by NIST and IBM. In Japan refer to the JIS X 0301 document. The ISO 8601 date format has already been in daily use in Scandinavia, parts of Eastern Europe, and most of the Far-East (Asia) for many years.

It will find usage in computer programs, log-books, contest entries, QSL cards, magazine reports, Web Pages, email, and many other places. The new format has already been adopted by many organisations. Astronomers have been using this method for over 200 years.

In Amateur Radio the proposal is already supported by: G3RZV, G6CGQ, GM4ANB, DL4EBY, DL8LAQ, G3XWH, G3RUH, G4NJH, G8IQU, HB9MAO, AA7BQ, N3EQF, KP2BL, WN4AZY, W1UD, W3IS, G8EXV, G0RUR, GM3JZK, G4IFB, N0ED (G3SQX), G3SEK, G0CUZ, G7LFC, 9M2CR, OH5IY, DL5BCU, G3TZO, G3OAF, G0BAF, VK3UM, G3NKS, G3PHO, EA2LU, K7BV, K2UYH, W6/PA0ZN, WA1LOU, G4HXH, and many others.


  1. An Introduction to using ISO 8601 in Amateur Radio can be found at:

  2. A general Proposal Document for Amateur Radio can be found at:
    http://www.qsl.net/g1smd/isoham.htm New Site.

  3. Intructions on how to set up computers to use the ISO 8601 format:

  4. A short summary of the ISO 8601 Date Format can be found at:

  5. A complete description of the ISO 8601 Standard can be found at:

  6. Background notes on the Year 2000 Problem can be found at:

  7. A list of the Countries that have adopted the ISO 8601 standard:
    http://www.qsl.net/g1smd/isoimp.htm New Site.

Other Internet Sites of Interest:


Year 2000 and ISO 8601.

The EME Newsletter Homepage

The Proposal is already supported by: Allen Katz K2UYH and Rein W6/PA0ZN.

The Proposal Document is also Reproduced in the 1998 September Issue (Vol 26, No 10) of their '432 MHz and Above EME News'.

See: 432 MHz and Above Newsletters