First Mass Day, or Araw ng Unang Misa, is observed in the Philippine province of Southern Leyte every March 31. This special working holiday commemorates the first documented Catholic Mass held in the Philippines on Easter Sunday in 1521, officiated by Father Pedro Valderrama during Ferdinand Magellan’s expedition. The Mass took place after Magellan and his crew arrived at what is believed to be Limasawa, where they established a friendship with local rulers. The site of the first Mass was declared a national shrine in 1960, and a shrine was built in 1984. Despite debates over the exact location of the first Mass, the event is a point of pride for the residents of Southern Leyte, with various activities held across the province to celebrate the occasion. President Rodrigo Duterte officially recognized March 31 as a special working holiday in 2019, allowing for commemorative events while employees do not receive a day off unless the holiday falls on a weekend.