Wikidata:Property proposal/latest end date

‎latest end date[edit]

Originally proposed at Wikidata:Property proposal/Generic

Done: ‎latest end date (P12506) (Talk and documentation)

Description	(qualifier) latest date on which the statement could have ceased to be true (i.e., latest date beyond which the statement could no longer be true)
Data type	Point in time
Example 1	Carrefour Socioculturel Au Vieux Théâtre (Q111846607)member of (P463)Association professionnelle des diffuseurs de spectacles RIDEAU (Q87727957) → latest start date (P8555) = 10 April 2022; latest end date = 8 February 2024
Example 2	Centre culturel francophone de Vancouver (Q111857120)member of (P463)Association professionnelle des diffuseurs de spectacles RIDEAU (Q87727957) → latest start date (P8555) = 10 April 2022; latest end date = 8 February 2024
Example 3	Le Petit Théâtre de Québec (Q111857177)member of (P463)Association professionnelle des diffuseurs de spectacles RIDEAU (Q87727957) → latest start date (P8555) = 10 April 2022; latest end date = 8 February 2024
Planned use	Maintenance of membership data
See also	end time (P582), latest start date (P8555), earliest end date (P8554), latest date (P1326)

Motivation[edit]

When uploading a dataset to Wikidata, it's not uncommon to stumble upon time-sensitive data points that lack time stamps. For example, when uploading an association's member directory, the "member of" relationship is hardly ever explicitly documented in the source database. It is rather implicit: the presence of an entity in the catalog indicates a membership status is true at the time of consulting the catalog. In such a scenario, one can use latest start date (P8555) to state that the membership status was true at the time of upload but most likely started at some earlier point in time before the upload date. This works quite fine for an initial upload. However, we lack a property to document an approximate end time when performing subsequent data maintenance uploads. My colleagues and I stumbled upon this challenge when re-uploading RIDEAU members from the Scène Pro (Q111597636) dataset: a handful of organization no longer are members in good standing of Association professionnelle des diffuseurs de spectacles RIDEAU (Q87727957)... but we do not know at which precise point in time their membership status came to an end. We only that their membership status is false at the time of extracting and loading the data to Wikidata. For this and other similar purposes, we believe it would be useful to introduce an end time property mirorring latest start date (P8555).

All three above examples are related to the Scène Pro data upload. If you have further examples from other use cases, please add them.