The ISO 8601 standard

ISO 8601 covers date and time-related data, including its exchange, transfer, and representation. It was first published in 1988, followed by multiple updates in 1991, 2000, 2004, and 2019. It aims to provide a system for the management of date and time data and the representation of individual elements to avoid numerical dates and times being misinterpreted, focusing on data transfer across countries and regions and emphasizing time zones and conventions that are specific to certain regions.

ISO 8601 divides the management into separate date and time models. The Date value is based on the Gregorian calendar (an international standard for civil use), while the 24-hour timekeeping system expresses the Time. It uses the principle that the greatest temporal granularity element should be the left-most one. Each following lesser element comes to the right of the previous one. For example, the year must precede the month, the month definition must precede the day...