ISO 8601specifies an internationally uniform format for date and time information. The standard is called "Data Elements and Interchange Formats; Information Interchange; Representation of Dates and Times" which can be translated as "Data elements and interchange formats, information interchange, representation of date and time".
It is also referred to as the international date format, which is reflected in the following notation: Year-Month-Day, and the same applies to the time: hours-minutes-seconds. In the basic format, the digits can be written directly, without separation, one after the other, or the individual groups of digits can be separated by separators. The date of October 30, 2005 has the notation 20051030 in the basic format, and 2005-10-30 in the extended format. The time is divided into the digits for the hours, minutes and seconds: 08:22:45.
With the standardization of the notation according to ISO 8601, the various traditional, country-specific notations of the date and time are to be eliminated, at least in information technology and electronic correspondence, since this leads to irritation.
ISO 8601 has been adopted as a European standard with the designation EN 28601 and has also been incorporated into the word processing standardized by DIN. The ISO notation is also used for the specification of time spans. Here, the start date followed by the letter "P" for period is separated from the time span. Example: A time span of four months, three days and two hours, starting from October 14, 2003 at 6:00 p.m. would thus have the following notation: 2003-10-14T18P4M3T2H.