The International Standard
Date and Time Notation:
ISO 8601
Official International Standard ISO 8601 (PDF)
Local copy
.
ISO 8601 standard
,
local copy
.
For those interested, there is also an ISO International Standard for Paper Sizes:
Remote copy
,
local copy
.
Revision date:
2007-12-07. (Please use
ISO 8601
, the International Standard Date and Time Notation.)