New Point-in-Time Legislative Databases from CanLII
"Users of these provinces' consolidated Acts and regulations now have access to versions as they came into force since 2004 or so, as well as to current versions updated weekly from governments' websites."CanLII now offers point-in-time legislation databases for the federal and all provincial governments and plans to add similar collections for the legislation of Canada's three Northern territories soon.
The databases make it possible to search a legislative text as it was legally binding on a particular date in the past, with historical coverage going back approximately five years.
It is also possible to compare two different versions of a particular document, note up statute and regulation sections and subscribe to RSS feeds to track legislative changes.