SECTION 1. The first day of Shawwal the tenth month of the Islamic calendar, is hereby declared a national holiday for the observance of Eidul Fitr, and the tenth day of Zhul Hijja, the twelfth month of the Islamic calendar is hereby declared a regional holiday in the Autonomous Region in Muslim Mindanao (ARMM) for the observance of Eidul Adha. Eidul Fitr is the first day marking the end of the thirty (30)-day fasting period of Ramadhan. Eidul Adha is a tenth day in the month of Hajj or Islamic Pilgrimage to Mecca wherein Muslims pay homage to Abraham's supreme act of sacrifice and signifies mankind's obedience to God.
The approximate date of these Islamic holidays may be determined in accordance with the Islamic calendar (Hijra) or the lunar calendar, or upon Islamic astronomical calculations, whichever is possible or convenient.