Under some metadata standards, time is a representation term used to specify a time of day in the ISO 8601 time format.
Note that Time should not be confused with the DateAndTime representation term which requires that both the date and time to be supplied.
A calendar date is a reference to a particular day represented within a calendar system. The calendar date allows the specific day to be identified. The number of days between two dates may be calculated. For example, "25 November 2024" is ten days after "15 November 2024". The date of a particular event depends on the observed time zone. For example, the air attack on Pearl Harbor that began at 7:48 a.m. Hawaiian time on 7 December 1941 took place at 3:18 a.m. Japan Standard Time, 8 December in Japan.
ISO 8601 is an international standard covering the worldwide exchange and communication of date and time-related data. It is maintained by the International Organization for Standardization (ISO) and was first published in 1988, with updates in 1991, 2000, 2004, and 2019, and an amendment in 2022. The standard provides a well-defined, unambiguous method of representing calendar dates and times in worldwide communications, especially to avoid misinterpreting numeric dates and times when such data is transferred between countries with different conventions for writing numeric dates and times.
In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has:
The modern 24-hour clock is the convention of timekeeping in which the day runs from midnight to midnight and is divided into 24 hours. This is indicated by the hours passed since midnight, from 00(:00) to 23(:59), with 24(:00) as an option to indicate the end of the day. This system, as opposed to the 12-hour clock, is the most commonly used time notation in the world today, and is used by the international standard ISO 8601.
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system, or to some arbitrary time in the past.
The ISO/IEC 11179 metadata registry (MDR) standard is an international ISO/IEC standard for representing metadata for an organization in a metadata registry. It documents the standardization and registration of metadata to make data understandable and shareable.
A representation term is a word, or a combination of words, that semantically represent the data type of a data element. A representation term is commonly referred to as a class word by those familiar with data dictionaries. ISO/IEC 11179-5:2005 defines representation term as a designation of an instance of a representation class As used in ISO/IEC 11179, the representation term is that part of a data element name that provides a semantic pointer to the underlying data type. A Representation class is a class of representations. This representation class provides a way to classify or group data elements.
A representation term is a word, or a combination of words, used as part of a data element name. Representation class is sometimes used as a synonym for representation term.
In metadata, the term date is a representation term used to specify a calendar date in the Gregorian calendar. Many data representation standards such as XML, XML Schema, Web Ontology Language specify that ISO date format ISO 8601 should be used.
ISO 2014 is an international standard that was issued in April 1976, and superseded by ISO 8601 in June 1988. ISO 2014 was the standard that originally introduced the all-numeric date notation [YYYY]-[MM]-[DD] with the digits in order starting with the most significant digit first. It was technically identical to ISO Recommendation R 2014 from 1971.
ISO 2015 is a standard of the International Organization for Standardization (ISO), superseded by ISO standard ISO 8601. The standard ISO week numbering system was introduced in ISO 2015. ISO 2015 was issued as an international standard in 1976, technically identical to ISO Recommendation R 2015, from 1971.
ISO 2711 is an ISO standard describing formats for ordinal dates. The ISO is an international standard-setting body composed of representatives from various national standards organizations. ISO 2711 was issued in 1973, and was superseded by ISO 8601 in June 1988.
ISO 3307 is an international standard for date and time representations issued by the International Organization for Standardization (ISO). The standard was issued in 1975, then was superseded by ISO 8601 in 1988.
ISO 4031 is a superseded international standard first issued in 1978 by the International Organization for Standardization. It defined the representation of local time differentials, commonly referred to as time zones. It has since been superseded by ISO 8601. This newer standard has set out the formats for local time differentials since 1988, so ISO 4031 is no longer in use.
Date and time notation around the world varies.
The Office Open XML file formats are a set of file formats that can be used to represent electronic office documents. There are formats for word processing documents, spreadsheets and presentations as well as specific formats for material such as mathematical formulas, graphics, bibliographies etc.
The European Committee for Standardization (CEN) and (CENELEC) adopted ISO 8601 with EN 28601, now EN ISO 8601. As a European Norm, CEN and CENELEC member states are obligated to adopt the standard as national standard without alterations as well.
Date and time notation in South Africa describes methods of expressing date and time used South Africa.
Date and time notation in Pakistan is based on the Gregorian and Islamic calendars. Pakistan has not officially adopted any time and date representation standard based on the ISO 8601.
ISO/IEC 19788Information technology – Learning, education and training – Metadata for learning resources is a multi-part standard prepared by subcommittee SC 36 of the joint technical committee ISO/IEC JTC 1, Information Technology for Learning, Education and Training.