Question: When did o canada become canada's national anthem?
Disambiguated questions and answers: question: When was o canada first used as canada's national anthem?|When did "O Canada" become Canada's de facto national anthem?
When did "O Canad"  become Canada's official national anthem?
answer: 1939
July 1 , 1980
1980
July 1, 1980
Natural Questions answer: July 1 , 1980 (from the Wikipedia article "O Canada")