213.1 All utilities which rely upon a proposed test year which includes forecasted data may update such data for changes which would have a significant impact on the filing. Except in extraordinary and well-explained circumstances as determined by the Commission, a utility will be limited to one update, and such update shall be filed, if at all, not later than twenty-one (21) days prior to the commencement of the hearings.

213.2 Within one hundred eighty (180) days of the completion of the rate proceeding, a utility shall file an actual historical cost-of-service study for the entire proposed test year.

SOURCE: Final Rulemaking published at 34 DCR 1155, 1177 (February 13, 1987).