March 1 is a Special Non-Working Day in Muntinlupa City as per Republic Act No. 9191, "An Act Declaring the First Day of March of every year as a Special Non-Working Day in the City of Muntinlupa to be known as the Muntinlupa City Charter Day."
Reference:
https://www.officialgazette.gov.ph/.../republic-act-no-9191/
