ISO 8601
ISO 8601 is a global standard that facilitates the exchange and communication of date and time-related information across the world. Developed and maintained by the International Organisation for Standardisation (ISO), it was initially published in 1988, with subsequent updates in 1991, 2000, 2004, and 2019, along with an amendment introduced in 2022. This standard offers a clear and precise method for representing calendar dates and times, aiming to prevent misinterpretation of numeric dates and times when data is shared among countries that follow different conventions.
The ISO 8601 standard encompasses various representations and formats, including dates in the Gregorian calendar (as well as the proleptic Gregorian calendar), times based on a 24-hour clock with an optional UTC offset, time intervals, and combinations of these elements. Importantly, the standard does not assign specific meanings to any components of the dates or times; their interpretation relies on the context in which they are used. Additionally, representations must avoid terms that lack a defined numerical meaning within the standard (such as references to years in the Chinese calendar) or that do not consist of computer characters (therefore excluding images or sounds).
In accordance with the ISO 8601 interchange standard, dates and times are organized so that the largest temporal unit (usually the year) appears first on the left, followed by each smaller unit to the right. These representations must utilize Arabic numerals and specific computer characters (like "‐", ":", "T", "W", "Z") that have designated meanings within the standard. Consequently, common descriptors such as "January," "Thursday," or "New Year's Day" are not permitted in interchange representations under this standard.