Use International Date Format (ISO) - Quality Web Tips

Here is a general suggestion and a request for everyone concerning the way that we write or type the date. You may expect that dates should be written as month first, then day and then finally year. This format is usually represented as MM/DD/YY or MM/DD/YYYY. Most people I know write or type the date this way as it is the way they have almost always seen it formatted. However, it may surprise you to know that this method is common to the United States, but is not used throughout the world. Sometimes, the day is first and then the month and year or some other arrangement. There is also an international method that should be used whenever possible. There are some good reasons why.

First off, knowing that dates can be interpreted differently than the USA standard method, you might be looking at a date written as 03/04/99 and you might wonder if this is March 4^th or April 3^rd of 1999. In fact, you don't even know if it is 1999 and not 2099 (or 1899 for that matter).

For usability and international acceptance there is a method of expressing dates that can be used physically --like when you fill out checks or other paperwork-- as well as digitally. This method uses YYYY-MM-DD or YYYY/MM/DD. This method makes sense because it lists the year first, and then the month and day. This goes from longest period of time, to the shortest and it is not as ambiguous. Switch to international date formatting on your computer, and for your web sites.

If you have administrator rights in Windows XP, you can change the setting on your computer to display the date correctly in this new format. First, open up the Control Panel and then look for the Regional and Language Options. Open this menu and look for the first Regional Options. The drop-down menu will most likely be set for English (United States). Click the Customize button and a new menu will open. On this window, look for the Date option and change the short date format to yyyy/MM/dd. Then the above example date of April 3^rd of 1999 would appear as 1999/04/03. It takes some getting used to, but it will work better for you in the long run.

Learn more about this concept as a web tip at w3.org.