The Sovereign's birthday has been celebrated in Canada since the reign of Queen Victoria (1837-1901).
May 24, Queen Victoria's birthday, was declared a holiday by the Legislature of the Province of Canada in 1845.
After Confederation, the Queen's birthday was celebrated every year on May 24 unless that date was a Sunday, in which case a proclamation was issued providing for the celebration on May 25.
An amendment to the Statutes of Canada in 1952 established the celebration of Victoria Day on the Monday preceding May 25.
From 1953 to 1956, the Queen's birthday was celebrated in Canada on Victoria Day, by proclamation of the Governor General, with Her Majesty's approval. In 1957, Victoria Day was permanently appointed as the Queen's birthday in Canada. In the United Kingdom, the Queen's birthday is celebrated in June.
In 2015 Victoria Day will be celebrated on Monday, May 18th.