The wrong time's right for him (6)
I believe the answer is:
mister
'him' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'the wrong time's right' is the wordplay.
'the wrong' indicates anagramming the letters.
'right' becomes 'r' (common abbreviation).
'times' anagrammed gives 'miste'.
'miste'+'r'='MISTER'
'for' is the link.
Can you help me to learn more?
(Other definitions for mister that I've seen before include "Male form of address" , "Form of address to a man, used without his name" , "Bloke" , "that's what you'd call him" , "Set rim (anag.)" .)