Busy time, seen in a harsh sort of light (4,3)

'busy time seen' is the definition.
I know nothing about this answer so I can't judge whether this works.

'harsh sort of light' is the wordplay.
I cannot really see how this works, but
'harsh' could be 'hard' (similar in meaning) and 'hard' is present in the answer.
'light' could be 'day' (I've seen this in other clues) and 'day' is located in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

'in a' acts as a link.

Can you help me to learn more?