Coming from Dave, perhaps, at the theatre (6)
I believe the answer is:
advent
'coming' is the definition.
(advent is the arrival or coming of something)
'dave perhaps at the theatre' is the wordplay.
'perhaps' indicates anagramming the letters.
'at' is a charade indicator (letters next to each other).
'the theatre' becomes 'NT' (National Theatre).
'dave' anagrammed gives 'adve'.
'adve'+'nt'='ADVENT'
'from' acts as a link.
(Other definitions for advent that I've seen before include "Coming, arrival" , "Pre-Christmas period" , "Christian season" , "sort of calendar" , "The season leading up to Christmas" .)