A moment in this month (7)
I believe the answer is:
instant
This clue is a double definition.
'a moment' is the first definition.
('instant' can be a synonym of 'moment')
'this month' is the second definition.
(I've seen this before)
'in' acts as a link.
(Other definitions for instant that I've seen before include "Sudden; moment" , "Precise moment" , "Sort of coffee" , "This coffee comes in powder form" , "like some coffee?" .)