It’s fitting in the bathroom to offer extra time (5)
I believe the answer is:
bidet
'it's fitting' is the definition.
(bathroom fitting)
'offer extra time' is the wordplay.
'offer' becomes 'bid' (synonyms).
'extra time' becomes 'et' (this might be a standard abbreviation which I don't know about).
'bid'+'et'='BIDET'
'in the bathroom to' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for bidet that I've seen before include "Cleaning vessel for privates" , "Stay behind" , "Bathroom basin" , "Washing facility" , "behind cleaner" .)