That would depend on whether you are still under the yearly contract or you've lived there long enough that it's switched to a month by month lease.
Many year leases have a clause that states that unless a certain amount of notice is given to terminate this lease at the end of the year, it automatically turns into a month by month tenancy. This avoids the necessity of having the renew the lease year after year.
To terminate a month by month tenancy, most states (not all by the way) require a 30 day written notice.
Gail