The date for the ened of your lease is determined by the presumed written document that you signed. As such, I recommend that you carefully read it in that its terms and conditions control the obligations owed to you by the landlord and vice versa in the absence of conflicting state law.If your commercial lease ends on a particular date, then most likely you need to vacate the unit by the end of the date that is the last day on the lease. If you need more time to vacate, you need to discuss this issue with your landlord and any agreement on this issue should be memorialized in writing.