Members of the military tradition, military officers, among the Young Turks revolted. The defense of their shrinking state had become a matter of intense professional pride which caused them to raise arms against their state. The event that triggered the Revolution was a meeting in the Baltic port of Reval between Edward VII of the United Kingdom and Nicholas II of Russia in June 1908. Though these imperial powers had experienced relatively few major conflicts between them over the previous hundred years, an underlying rivalry, otherwise known as "the Great Game", had exacerbated the situation to such an extent that resolution was sought. The Anglo-Russian Convention of 1907 brought shaky British-Russian relations to the forefront by solidifying boundaries that identified their respective control in Persia  and Afghanistan. Military officers fearing the meeting was a prelude to the partition of Macedonia, Army units in the Balkans mutinied against Sultan Abdülhamid II. A desire to preserve the state, not destroy it, motivated the revolutionaries. The revolt began in July 1908. Major Ahmed Niyazi, fearing discovery of his political moves by an investigatory committee sent from the capital, decamped from Resen on 3 July with 200 followers demanding restoration of the constitution. The sultan's attempt to suppress this uprising failed due to the popularity of the movement among the troops themselves. Rebellion spread rapidly due to the ideology of Ottomanism. On 24 July, sultan Abdul Hamid II capitulated and announced restoration of the 1876 constitution.
Question: How many days did the rebellion of 1908 last?
Answer: 21