Label: Date – A date associated with an event in the life cycle of the resource. Typically, Date will be associated with the creation or availability of the resource. Recommended best practice for encoding the date value follows the YYYY-MM-DD format. If the full date is unknown, month and year (YYYY-MM) or just year (YYYY) may be used.

Examples:
Date=”1998-02-16″
Date=”1998-02″
Date=”1998″