Somalia gained independence in 1960 after the former colonies known respectively as British Somaliland and Italian Somaliland united on the 1st of July of that same year to form a single homogeneous nation. The northern part of Somalia was formerly known as British Somaliland and the southern part of the country was referred to as Italian Somaliland. But please remember, no borders existed in the African continent before the European powers divided Africa among themselves.
After the assassination of President Abdirashid Ali Shermarke at Las Anod airstrip, Major General Mohamed Siyad Barre engineered a coup that brought him to power on the 21st of October, 1969 until the breakout of hostilities in 1991 when he was deposed by the United Somali Congress (USC) headed by General Mohamed Farah Aideed. Under Siyad Barre Somalia progressed militarily and many sectors of the economy saw tremendous growth despite bad politics tarnishing the regime's image.
Thus, the 21st of October was a major holiday during the tenure of Siyad as president of the Somali republic. Besides the two Islamic festivities of Eid-ul-fitr and Eid-ul-adha, Somalis have forgotten national celebrations altogether.