Re Downes & Lobbs’ Contract, Downes v Lobbs An agreement in writing giving an option to purchase land contained the following clause as to its duration and determination: “the option shall operate for three years certain from the date hereof and after the expiration of that time may be determined by the grantor giving to the grantee 12 months’ notice to terminate at the expiration of the said term or at any later dateâ€:—