Datumangivelse

Datumangivelse is the specification of a date related to a document, event, or data item. It provides temporal context and enables ordering, filtering, and interpretation of information. In library, archival, and data-management practice, the datum helps users understand when something occurred, was created, published, or modified.

Dates can be expressed at different levels of precision. A precise date might be a single day, such as 2023-07-15. A partial date could be just a year (1999) or year and month (1999-05). Dates can also be given as ranges, for example 2010-2012, or as approximate values with qualifiers such as ca. 1800 or about 1995. In metadata, qualifiers are often stored separately from the actual date to preserve data integrity and to support automated processing.

Standards and encoding practices emphasize unambiguous representation. ISO 8601 is commonly recommended for numeric dates (YYYY-MM-DD, YYYY-MM, etc.), while metadata schemes like Dublin Core, METS, MODS, and EAD provide structured elements to record both the date and any qualifiers or uncertainty. It is also common to separate the core date from notes or provenance information that explain the context or level of certainty.

Applications span libraries, archives, museums, and research data repositories. Accurate datumangivelser support discovery, citation, provenance tracking, and temporal analyses, while careful handling of uncertain or approximate dates helps maintain reliability in records and datasets.