There's to-do, then, about being punctual (2,3,3)
I believe the answer is:
on the dot
'punctual' is the definition.
(I've seen this before)
'there's to-do then about' is the wordplay.
'there's' is a charade indicator (letters next to each other).
'about' indicates anagramming the letters.
'to'+'do'='todo'
'todo' next to 'then' is 'todothen'.
'todothen' is an anagram of 'ON THE DOT'.
'being' is the link.
(Other definitions for on the dot that I've seen before include "Precisely punctual" , "Sharp" , "Prompt" , "At exactly the right time" , "on precise place in line?" .)