The first ADS-B deadline in Canada is
January 1, 2021. Until then, no ADS-B is required anywhere in Canada.
Thereafter, until
January 1, 2022, ADS-B is only required in Canada in Class A airspace, which is all at or above 18,000 feet (and starts even higher in the far north, above 72 degrees latitude).
After January 1, 2022, ADS-B is required in Canada in Class A and B airspace, and it must be the 1090ES ADS-B and have antenna diversity (antenna on both top and bottom of aircraft).
Here's
a good summary for those who want to read more.
Hope this helps those flying into Canada
Dan