Canadian Open Mathematics Challenge (open to all):
September 3rd: registration opens
October 16th: shipped exam registration deadline
October 24th: pdf delivery registration deadline
October 30th: contest date in North/South America
Asian Pacific Mathematics Olympiad (invite only):
March 10th afternoon: contest date in North America
Canadian Mathematical Olympiad (invite only):
TBD (early March)
Canadian IMO team selection test (invite only):
TBD (mid April)