This term is proposed for full integration into Schema.org, pending implementation feedback and adoption from applications and websites.

Thing > Property > legislationDateVersion

The point-in-time at which the provided description of the legislation is valid (e.g. : when looking at the law on the 2016-04-07 (= dateVersion), I get the consolidation of 2015-04-12 of the "National Insurance Contributions Act 2015")
Values expected to be one of these types
Used on these types