Legal Question in Landlord & Tenant Law in California

Having prevented the owner from being able to rent the unit to someone else, probably for at least a month before they would move in if not more likely 6 weeks [they have to give 30 days notice to their current landlord and few people move during the Christmas season], and not telling them until after your scheduled move in date, why would you think you could breach the agreement without having to pay something? You are liable for the term of the lease, with the landlord having to use reasonable diligence to mitigate the damages by trying to find another renter. Since you waited until after the lease was to start, do not expect them to cut you any slack. They will demand full payment for the first month and the security deposit. Your not having paid anything yet does not matter as to your contractual obligations.