When to leave African country to chase exotic item (4,2,2)

'when' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'to leave african country to chase exotic item' is the wordplay.
I cannot quite understand how this works, but
'to' is found in the answer.
'leave' could be 'go' (to go is to depart or leave) and 'go' is found within the answer.
an anagram of 'item' is 'time' which is within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?