ISO 8601
ISO 8601 is an international standard for representing dates and times in a clear, unambiguous numerical format.
ISO 8601 is an international standard for representing dates and times in a clear, unambiguous numerical format. It is used in data exchange to reduce confusion caused by regional differences in date ordering, time zones, and notation. The standard is designed to reduce ambiguity in international communication and machine-readable data exchange.
Purpose and scope
ISO 8601 provides a standardized numeric representation of dates and times for information interchange. It is intended to prevent misunderstandings that can arise from differing regional date conventions and time-zone practices. The standard covers Gregorian calendar dates, 24-hour times, UTC offsets, intervals, and recurring intervals.
Format structure
The standard uses a prescribed component order, beginning with year and followed by month and day for dates, and hour, minute, second, and fractional seconds for times. It also defines formats for calendar, ordinal, and week-based dates. Common examples include a date such as 2022-09-27 and a date-time such as 2022-09-27 18:00:00.000.
Revisions and editions
ISO 8601 was first published in 1988 and has been revised several times. Sources identify later versions including 2004 and the ISO 8601-1:2019 split, with a 2022 amendment noted in secondary sources.
Uses in computing
ISO 8601 is widely used in software systems, APIs, databases, and protocols because it is machine-readable and reduces locale-dependent ambiguity. It is often recommended for plain-text data interchange.
Key facts
- ISO 8601 defines a numeric way to write dates and times that is intended to be globally understood.
- The standard orders date components as year, month, day, and time components as hour, minute, second, and fractional second.
- It covers calendar dates, ordinal dates, week dates, local time, UTC time, time offsets, time intervals, and recurring time intervals.
- ISO 8601 has been updated over time, with revisions noted in 1991, 2000, 2004, 2019, and an amendment in 2022.
- Common examples include a date such as 2022-09-27 and a date-time such as 2022-09-27 18:00:00.000.
ISO 8601 is relevant to Canadian readers because it is widely used in Canadian government and software contexts for machine-readable dates and times; Canadian English usage often benefits from a standard that avoids day-month versus month-day ambiguity.[11]
Frequently asked questions
What is ISO 8601?
What is the basic date format in ISO 8601?
What does ISO 8601 cover besides calendar dates?
When was ISO 8601 first published?
Is ISO 8601 used in computing?
References
- ISO — https://www.iso.org/iso-8601-date-and-time-format.htmlSupports: Official overview of ISO 8601 purpose, date order, and covered representations.
- Wikipedia — https://en.wikipedia.org/wiki/ISO_8601Supports: Summary of publication history, scope, and revisions of the standard.
- ISO — https://www.iso.org/standard/40874.htmlSupports: ISO 8601:2004 scope, including calendar, ordinal, and week dates; time intervals and recurring intervals.
- NASA FITS — https://fits.gsfc.nasa.gov/iso-time.htmlSupports: Explanation of numeric date/time notation and its role in avoiding confusion in communication and computing.
- UK Government — https://www.gov.uk/government/publications/open-standards-for-government/date-times-and-time-stamps-standardSupports: Use of ISO 8601 for machine-readable dates and times in government systems.