Canadian Politics Today

A couple of other notes about the clause:

- Only certain rights can be overridden. For example, they can override the right to freedom of expression (as Quebec did with bill 101), but they can't override rights related to democracy/voting

- The notwithstanding clause expires after 5 years, but can be renewed indefinitely. For example, when Quebec brought in bill 101, they invoked Nothwithstanding (although they were doing that with pretty much every bill at the time.), They've had to continually invoke it every few years, otherwise their language laws might become unconstitutional. (The reason why it expires after 5 years is probably because that's the maximum length of time a legislature can sit, and it forces the next government to deal with the issue in some way, be it fixing the legislation to make it constitutional or reinvoking the notwithstanding clause.)

Quebec, Saskatchewan, and the Yukon are so far the only ones to have successfully used it. Alberta tried with regard to same sex marriage legislation but were snubbed as the definition of marriage was deemed to be within the exclusive domain of the Parliament of Canada.

And you are correct, the 5 year limit concurs with the maximum time of a leg. can sit between elections.