Nueva Vizcaya Day, also known as the Ammungan Festival, is observed in the province of Nueva Vizcaya in the Philippines every May 24. This special non-working holiday commemorates the founding anniversary of the province, which was established in 1839. The festival celebrates the rich cultural heritage and diversity of the region, showcasing its 18 indigenous ethnic groups, including the Bugkalot, Dumagat, Gaddang, and Ifugao peoples. The Ammungan Festival features a week-long series of events culminating on May 24, including a Grand Parade, street dances, traditional games, agricultural shows, artisan fairs, and ethnic music performances. The term "Ammungan," meaning "gathering" in the Gaddang language, emphasizes unity among the local communities. The capital of Nueva Vizcaya, Bayombong, serves as the primary venue for many of these activities.