Brazil, Mother's Day is celebrated on the second Sunday of May.
The first Mother's Day in the country was promoted by Associação Cristã de Moços de Porto Alegre (Young Men's Christian Association of Porto Alegre), on May 12, 1918. In 1932, the then-President Getulio Vargas made official the date on the second Sunday of May. In 1947, Archbishop Jaime de Barros Chamber, Cardinal-Archbishop of Rio de Janeiro, determined that this date was also included in the official calendar of the Catholic Church.
It's considerated an unofficial holiday (see Public holidays in Brazil).