My question involves landlord-tenant law in the State of: California

Hi,
I gave a 30 day notice to my landlord and he informed me that I still have 2 months left on my lease. I moved in on 2/1/2011 under the assumption that I would rent for a total of 13 months(to help the landlord during the slow season) and would move out 2/28/2012. The problem is that on the lease it states two conflicting dates. The first, states "for a term of 1 and 1/12 years - which equals 13 months. The second date states that my lease will end "3/31/2012". Do I have a case to terminate the lease 2/28/2012 rather than 3/31/2012?!?!? Any help would be greatly appreciated.
Brandon