Unlike the FAA's "refer-madness" approach of considering a pilot a "substance abuser" if they smoked marijuana once in their life, Canada takes a much more modern approach. First Cannabis is completely legal in Canada and with that Transport Canada instituted a policy of allowing anyone who has consumed Cannabis products in the past to be allowed to fly aircraft for as long as their most recent consumption was a least 28 days from taking the controls. https://tc.canada.ca/en/aviation/general-operating-flight-rules/better-pilot-decision-making/cannabis-legalization
While obviously this will prevent habitual users from becoming pilots and no one should be intoxicated with any substance before driving or flying, many have argued that 14 days for once in a blue moon cannabis consumers is more than enough time for the THC to leave one's system. However the policy of "baring pilots from flying for 28 days after consuming cannabis products" is far better than the current reefer-madness policy by the FAA. https://www.cbc.ca/news/business/transport-canada-cannabis-1.5164518 This also includes "Broad Spectrum CBD" which does not contain THC and thus does not have any of the psychedelic effects of marijuana but does have therapeutic benefits such as bone decalcification and pain management.
Joe Rogan pointed out that DUI's went down in states with legalized cannabis