Extension of zoning requirements and general terms and conditions for minor site plan. The Planning Board shall grant an extension of the two-year period for a period determined by the Board but not exceeding one year from what would otherwise be the expiration date, if the developer proves to the reasonable satisfaction of the Board that the developer was barred or prevented, directly or indirectly, from proceeding with the development because of delays in obtaining legally required approvals from other governmental agencies and that the developer applied promptly for and diligently pursued the approvals. A developer shall apply for this extension before what would otherwise be the expiration date, or the 91st day after the date on which the developer receives the last of the legally acquired approvals from the other governmental agencies, whichever occurs later.