When did O, Canada officially become the national anthem?

"O Canada" officially became the national anthem of Canada in 1980. Prior to that, it had been intermittently used as the country's unofficial national anthem since the late 19th century. However, it was not until March 15, 1967, that the anthem was first performed at an official event to celebrate Canada's centennial, gaining recognition as a potential national anthem. It took another thirteen years of debate and discussion before "O Canada" was officially adopted by the Canadian government as the country's national anthem through a proclamation by Queen Elizabeth II on July 1, 1980. Thus, 1980 marks the year when "O Canada" attained its formal status as the national anthem of Canada.