Dark hours, fight with adversary going badly (9,5)

I believe the answer is:

graveyard shift

'dark hours' is the definition.
(work shift done at night)

'fight with adversary going badly' is the wordplay.
'with' is a charade indicator (letters next to each other).
'going badly' indicates anagramming the letters.
'fight'+'adversary'='fightadversary'
'fightadversary' with letters rearranged gives 'GRAVEYARD SHIFT'.

(Another definition for graveyard shift that I've seen is " work so late".)

I've seen this clue in The Times.

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