23 September was first observed when King Faisal issued a royal decree on 21 August 1965 that declared the day to be celebrated at official levels as per the Gregorian calendar. In 2005, King Abdullah issued a royal decree that officially declared it a national holiday from 2007 onwards. The number of lunar, not solar, years are commemorated.

First National Day

King Abdulaziz was able to conquer the oases of Riyadh in 1902; and al-Hasa in 1913, and by 1925, he unified both Nejd and the Hejaz after defeating the forces of Sharif Hussein. On 23 September 1932, King Abdulaziz changed the name of his realm to his family name, the House of Saud.🇸🇦🇸🇦