Almost thirty-one days needed to make this brandy (4)
I believe the answer is:
marc
'this brandy' is the definition.
(marc is a kind of brandy)
'almost thirty-one days' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'thirty-one days' becomes 'March' (March has 31 days).
'march' with its last letter taken off is 'MARC'.
'needed to make' is the link.
(Other definitions for marc that I've seen before include "A brandy; --- Chagall, artist" , "Brandy made from fruit-refuse" , "Brandy made from wine press residue" , "Drink" , "Cram (anag.)" .)