Future commanding officer and king for thirty-one days (7)
I believe the answer is:
october
'thirty-one days' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for october that I've seen before include "The Hunt for Red . . . . . . . (film)" , "Bore cot out at this time" , "could be a revolution" , "Revolutionary period" , "Russian Revolution month" .)