While some acts come into force on Royal Assent, many require Proclamation or an Order in Council to do so. A number of provinces publish tables that let you see if a specific act has been proclaimed.
Federal: Go to LEGISinfo, find your act and then click on the link for Coming into Force information. You can also check the Table of Public Statutes and Responsible Ministers which lists all the coming into force information for the consolidated version of an act.
British Columbia: Go to the Regulations Bulletins and look under “Acts in Force” on the Cumulative Regulations Bulletin. As with the Alberta Gazette, you will have to do this year by year.
Newfoundland and Labrador: http://www.assembly.nl.ca/legislation/sr/lists/Proclamation.htm
Nunavut: You can find in force dates in the Table of Public Acts.
Prince Edward Island: You can find in force dates in the Table of Public Acts.
Saskatchewan: The Saskatchewan Gazette, Part I lists both acts proclaimed that year and acts still waiting to be proclaimed.
(My apologies to New Brunswick: I wasn’t able to find a table of in force dates.)