The period commencing on the date (“ Commencement Date ”) which is the later of (a) the date the lease is executed by, and delivered to, both parties, or (b) the date Landlord delivers to Tenant possession of the Premises with Landlord’s Work, if any, substantially complete or any earlier date on which Tenant first occupies any part of the Premises for the conduct of business, and ending on the date (the “ Expiration Date ”) which is the earlier of (i) last day of the month in which occurs the tenth (10 th ) anniversary of the day immediately preceding the Commencement Date (“ Fixed Expiration Date ”), or (ii) the date the term of this lease is terminated pursuant to this lease (“ Earlier Expiration Date ”).