Davao Region Day, observed in the Philippine provinces of Davao del Norte, Davao Oriental, and Davao del Sur, is a special non-working holiday celebrated every July 1. This day commemorates the split of Davao Province into three separate provinces in May 1967, marking the establishment of the Davao Region, officially designated as Region XI. The name "Davao" is believed to be derived from names used by three different aboriginal tribes for the Davao River. The region has a rich history, having been part of the Sultanate of Maguindanao before Spanish colonization began in the mid-19th century. Although the provinces of Davao de Oro and Davao Occidental were created later and do not celebrate this holiday, the three original provinces honor their founding through various local festivities and observances.