The zoning requirement and general terms and conditions, whether conditional or otherwise, upon which minor site plan approval was granted, shall not be changed for a period two years after the date of minor site plan approval. The Approving Authority shall grant an extension of this 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 entities and that the developer applied promptly for and diligently pursued the approvals. A developer shall apply for this extension before: 1. what would otherwise be the expiration date, or (2) the ninety-first day after the date on which the developer receives the last of the legally required approvals from the other governmental entities, whichever occurs later.