The Extended Date/Time Format (EDTF) is a standard digital way for listing dates and times

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

On this blog I refer to dates for articles, etc. in the usual American format of Month_ Day,_Year. But I am aware that the British instead put the Day first.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There is a standard way of listing dates and times using only numbers called the Extended Date/Time Format (EDTF), as shown above, with dashes between date items and colons between time items using a 24-hour clock.

 

The Library of Congress has an article on February 4, 2019 about this Extended Date/Time Format (EDTF). And Wikipedia has a page on the International Standard for it, which is ISO 8601. Markus Kuhn at the NASA Goddard Space Flight Center has an article with A summary of the international standard date and time notation.

 

Finally, there is a very detailed 23-page pdf article by Annamarie C. Klose, Scott Goldstein, and Morris S. Levy in Library Resources and Technical Services on October 2025 titled It’s About Time and subtitled Use of the Extended Date/Time Format in the Digital Public Library of America.