Time to be part of campaign I never rejected (7)
I believe the answer is:
evening
'time' is the definition.
(I've seen this before)
'part of campaign i never rejected' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'rejected' says the letters should be written backwards.
'gnineve' can be found hidden inside 'campaign i never'.
'gnineve' backwards is 'EVENING'.
'to be' acts as a link.
(Other definitions for evening that I've seen before include "somewhat late in the day" , "Balancing" , "Late time of day" , "Early night" , "Late afternoon" .)