Not whom you wish to escort and not when (5,4)

'not when' is the definition.
I don't know anything about this answer so I cannot judge whether this works.

'not whom you wish to escort and' is the wordplay.
I cannot really see how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
'escort' could be 'date' (synonyms) and 'date' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?