Criminal's head down before sentence, it's said behind bars (7,4)

I believe the answer is:

closing time

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

'said behind bars' is the definition.
The definition suggests a singular noun which matches the answer.

'criminal's head down before sentence' is the wordplay.
'head' suggests taking the first letters.
'down' becomes 'losing' (similar in meaning).
'before' means one lot of letters go next to another.
'sentence' becomes 'time' (a prison sentence).
The initial letter of 'criminals' is 'c'.
'c'+'losing'+'time'='CLOSING TIME'

'it's' acts as a link.

Can you help me to learn more?

(Other definitions for closing time that I've seen before include "when the pub shuts" , "End of (drinking) session" .)

I've seen this clue in The Telegraph.

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