Right on time, note (5)
I believe the answer is:
fiver
'note' is the definition.
(I know that fiver is a type of note)
'right on time' is the wordplay.
'right' becomes 'r' (abbreviation).
'on' says to put letters next to each other.
'time' becomes 'five' (I can't justify this - if you can you should believe this answer much more).
'r' after 'five' is 'FIVER'.
Can you help me to learn more?
(Other definitions for fiver that I've seen before include "paper ready" , "Where to see portrait of Elizabeth Fry" , "Smallest English note" , "money" , "Note worth 500p" .)