When you see reports of the daily percentage change on the S&P500 mini , what are the open and close times? My trading platform calculates from midnight to midnight GMT but that is obviously not in line with what the actual time settings are. The CME Globex website states: Sunday - Friday 6:00 p.m. - 5:00 p.m. Eastern Time (ET) Trading halt 4:15 p.m. - 4:30 p.m. Does this mean that 4:30 p.m ET is the start of the new day? So daily from 4:30 p.m. to the following day at 4:15 p.m is the calculation range? Thanks.