OMG, I totally forgot about this spin-off :? Can I still send an entry?
Spin-off is more flexible about DDL. It depends on the host if he has done the whole job already or not. It has happened before that entries sent after DDL has been accepted.
So, I suggest you to send your entry to the host just in case. You don't lose anything doing that, but yiu can save sometime to the host in case your enrry is accepted. Don't forget to qrite the book/novel/poem/etc. that inspired the song you will send.
Later on the host will let you know.