Yes, the commitment to phase out coal was announced in 2016, and then the regulations followed. In terms of the actual implementation—which is ongoing in Alberta, where there has already been the transition—I would say 2016 in terms of notice from themselves and perhaps 2015 in terms of notice from the international community, because the Paris Agreement includes wording about the necessity for a just transition.
On April 28th, 2022. See this statement in context.