Lighting up time! (5)

I believe the answer is:

night

I'm a little stuck... Click here to teach me more about this clue!

'time' is the definition.
(I know that night is a type of crepuscle)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for night that I've seen before include "A Hard Day's (the Beatles)" , "See 1 Across" , "Saturday -- Fever (film)" , "That's when it's darkest" , "follow-up to 16 [TWILIGHT]" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app