Tried to find this info, but I'm probably not a good "searcher". When the NW and CO computers do the EUA at "midnight", is this midnight Eastern time (EWR/DTW), Central time (IAH/MSP), midnight in the time zone where the flight originates, midnight where the passenger resides or some other possibility??

At DL, they used to refer to 24/72 hours before in the timezone of the flight departure.

Thanks in advance....wondering so I can time the call to NW when the CO EUA doesn't process.