Jasaan Day (Araw ng Jasaan) is observed in the municipality of Jasaan, Misamis Oriental, Philippines, every September 1. This special non-working holiday commemorates the founding anniversary of Jasaan, which was officially reinstated as a municipality on September 1, 1948, following its downgrade to a barrio in 1903. The name "Jasaan" originated from a misunderstanding between a Spanish missionary and a local man, leading to the misinterpretation of the local term "Ag-hasaa." The Jesuits began constructing a church in the area in 1723, which was completed in 1830 and is now represented by the Immaculate Conception Parish Church. Today, Jasaan has a population of over 57,000 and consists of 15 barangays, with a mix of coastal and inland communities. The municipality is known for its agro-industrial activities and natural springs that attract visitors.