core + pending (Pending Extension): these terms are pending wider review. Feedback is welcomed!

sdDatePublished

Defined in the pending.schema.org extension.
Canonical URL: http://schema.org/sdDatePublished

Thing > Property > sdDatePublished

Indicates the date on which the current structured data was generated / published. Typically used alongside sdPublisher
Values expected to be one of these types
Date
Used on these types
CreativeWork

Source

https://github.com/schemaorg/schemaorg/issues/1886

Schema Version 3.4.