wgolemboski@nyiso.com writes to the NYISO_TECH_EXCHANGE Discussion List:

The NYISO is reserving hour beginning 13:00 in the April 21, 2001 Real-Time
Market, as well as the following hours per ECA20001006B to verify prices:

PJM: 1:00, 2:00, 6:00
OH:  1:00, 2:00, 6:00
HQ:  1:00 - 6:00
NE:  1:00, 2:00, 6:00, 23:00

Prices in the April 22, 2001 Day-Ahead Market are correct.