Va. Code § 5.1-134
No change shall be made in any rate, fare, charge, or classification, or any rule, regulation, or practice affecting such rate, fare, charge, or classification, or the value of the service thereunder, specified in any effective tariff of a common carrier or restricted common carrier by aircraft, except after thirty days' notice of the proposed change, filed and posted in accordance with § 5.1-132. Such notice shall plainly state the change proposed to be made and the time when such change will take effect. The Commission may, in its discretion and for good cause shown, allow such change upon notice less than that herein specified or modify the requirements of this section and § 5.1-132 with respect to posting and filing of tariffs either in particular instances or by general order applicable to special or peculiar circumstances or conditions.
Va. Code § 5.1-134