Occur, strangely enough, around Nov 1st, you'll agree (6)
I believe the answer is:
concur
'agree' is the definition.
(I know that agree can be written as concur)
'occur strangely enough around nov 1st' is the wordplay.
'strangely enough' is an anagram indicator.
'around' means one lot of letters goes inside another.
'nov 1st' becomes 'n' (1st letter of 'nov').
'occur' anagrammed gives 'cocur'.
'cocur' going around 'n' is 'CONCUR'.
'you'll' acts as a link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for concur that I've seen before include "See eye to eye" , "Give assent" , "Be in accord" , "meet" , "Stone pile" .)