As authorized in the introductory text of clauses FAR 52.243-1, Changes - Fixed-Price; FAR 52.243-2, Changes - Cost-Reimbursement; and FAR 52.243-4, Changes, and in the prescription at FAR 43.205(c) for FAR 52.243-3, Changes - Time-and-Materials or Labor-Hours, the contracting officer may vary the period within which a contractor must assert its right to an equitable adjustment but the extended period shall not exceed 60 calendar days.