Long layover in Helsinki and shortage of appointments at Finland consulate New York

[aviksamanta012345]

Hello people..i have an upcoming trip in December and i have 11 hours stopover in Helsinki in my onward journey and 23 hours in the return journey. I started applying for a schengen tourist visa about a week back but the first appointment that they have available is on 4th December (which i booked) and i am supposed to travel on 15th december. Do you guys see a big risk in applying for the visa in the sense that i may not get back my passport by 15th?