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

Abstract

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.