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

The NYISO is reserving hours-beginning 0, 3, 5-6, 8-18, and 20 in the 11
May 2001 real-time market to verify prices.
Prices for the 12 May 2001 Day-Ahead market are correct.
Pursuant to ECA-B the NYISO is reserving the following hours at the
following external proxy buses:
PJM:  0, 2-4, 21
OH:  21
HQ:  21
NE:  21