Tiny Dickensian character welcoming time with sweet birds (7)
I believe the answer is:
titmice
'birds' is the definition.
(titmouse is a kind of bird)
'tiny dickensian character welcoming time with sweet' is the wordplay.
'tiny dickensian character' becomes 'tim' (Tiny Tim from Charles Dickens' A Christmas Carol).
'welcoming' is an insertion indicator (in sense of 'inviting in').
'time' becomes 't' (abbreviation).
'with' means one lot of letters go next to another.
'sweet' becomes 'ice' (ice is a kind of sweet).
'tim' enclosing 't' is 'titm'.
'titm'+'ice'='TITMICE'
(Other definitions for titmice that I've seen before include "Small, active songbirds" , "Little singers" , "little birds" , "Small birds" .)