As authorized in the prefaces 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 43.205(c) for FAR 52.243-3, Changes—Time-and-Material or Labor-Hours, the period within which a contractor must assert its right to an equitable adjustment may be varied not to exceed 60 calendar days.