Sagay City Charter Day is observed in Sagay, Negros Occidental, Philippines, every June 11. This special non-working holiday commemorates the anniversary of Sagay’s conversion from a municipality to a city, a change that was officially enacted in 1996. The city, originally founded as Argüelles in 1860, underwent several name changes and administrative shifts during its history, particularly during the Spanish colonial period and later under American rule. Sagay experienced significant economic growth due to the development of the lumber and sugar industries, attracting migrant laborers and contributing to its ethnic diversity. The day celebrates the signing of the law that established Sagay as a city, and it should not be confused with Sagay Foundation Day, which is celebrated on July 31 in a different municipality.