### Clue: Desert army having commitment for final day of circumnavigation (9)
### Answer: EIGHTIETH 
 ### Explanation: Definition: final day of circumnavigation
  EIGHTH(reference to the 8th Army of the British Army, best known for their north African desert campaign in WW2, especially the Battles of El Alamein) **containing**(having) TIE(bond,commitment)
Answer:  Reference to the final day of Phileas Fogg's and Passepartout's global circumnavigation in Jules Verne's Around the World in 80 Days.