It’s About Time: Use of The Extended Date/Time Format in the Digital Public Library of America

Date metadata can be a powerful tool for browsing, search, and visualization. Although metadata quality and consistency are key, a broad array of practices exists in the Libraries, Archives, and Museums (LAMs) community’s metadata, which is stored in repositories, library catalogs, and other platforms. Cultural heritage materials with “squishy” dates can be difficult to express and display. While institutions may find local approaches, challenges arise when the metadata is shared elsewhere. The Extended Date/Time Format (EDTF) is a solution to encode dates that conform to a broad variety of scenarios, including ambiguous and circa dates. This article assesses the impact of EDTF in the Digital Public Library of America (DPLA), an aggregator of LAMs metadata. Compared to a prior study in 2015, date values that correspond with EDTF have increased. The overall number of records with any date value, however, has declined. The authors note nuances regarding the results and provide recommendations for the community.