The Commencement Date is a critical contractual milestone that triggers contractual obligations including the start of time for completion. For clarity and enforceability, it must be specified clearly in contract documents forming part of the formal contract. The Contract Agreement (Option B) and the Particular Conditions (Option C) are the standard places to unambiguously specify the Commencement Date.

Minutes of meetings (Option A) or emails (Option D), while useful for informal communication, do not have the legal certainty or binding contractual effect unless expressly incorporated into the contract documents. Therefore, specifying the Commencement Date solely in meeting minutes or emails is not advised for clarity and risk mitigation.