A date is a calendar date as an ISO 8601 string, YYYY-MM-DD (for example 2026-08-26). It refines string, so the value is still plain text on the wire. format: date makes an editor show a date picker instead of a text box, and a pattern lets a validator check the shape without parsing.

This page describes the date type, a value type of Hypermedia Schemas. Its formal schema is attached as the schemaDefinition in this document's metadata, so the app can show it and create values of this type.

See also

date-time: an instant with a time of day.

timestamp: the Unix-millisecond time inside blobs.

string: the underlying kind.

Scalar schema: how format and patterns refine a string.