Has the meaning given to that term in BC1 of the Grid Code. Is either the minimum time that a BM Unit which has been exporting must operate at zero or be importing, before returning to exporting; or the minimum time that a BM Unit which has been importing must operate at zero or be exporting before returning to importing, as a result of a Bid-Offer Acceptance, expressed in minutes. Also set of data supplied by the System Operator for publication on the BMRS, comprising for each BM Unit the effective time and the Minimum Zero Time.