Almost ahead of schedule after November (6)
I believe the answer is:
nearly
'almost' is the definition.
(I know that almost can be written as nearly)
'ahead of schedule after november' is the wordplay.
'ahead of schedule' becomes 'early' (I've seen this before).
'after' says to put letters next to each other.
'november' becomes 'N' (phonetic alphabet: alpha, bravo, charlie etc.).
'early' after 'n' is 'NEARLY'.
(Other definitions for nearly that I've seen before include "Noon at eleven fifty nine am" , "parsimoniously" , "Close" , "More or less" , "pretty much" .)