Dealt with note before month is over (5)
I believe the answer is:
faced
'dealt with' is the definition.
(facing is a kind of dealing with)
'note before month is over' is the wordplay.
'note' becomes 'fa' (fourth note in sol-fa notation: doh, ray, me...**).
'before' means one lot of letters go next to another.
'month' becomes 'dec' (Dec is an example).
'is over' shows that the letters should be reversed in order.
'dec' backwards is 'ced'.
'fa'+'ced'='FACED'
(Other definitions for faced that I've seen before include "Confronted" , "Resisted" , "Dealt with" , "Stood up to" , "Stomached" .)