Explain the Upgrade Please
 

Domestic Itinerary on deeply discounted fare (T) for next day travel.

Both segments on regional jets.

About 22 hours before scheduled flight time 12 noon central time, did a no-charge (PLAT) change-this is called same day change, and moved to a flight that was about an hour later than the original.

New itinerary segment #2 has an upgradable aircraft. Time now, about 23 hours before flight time, of new flight.

Within an hour of the change, I get the email upgrade notification.

I thought the policy was that I would have to wait until after midnight for EUA to run. I am glad it happened, but why?

Runs approximately 24 hours before departure time. So if this new flight is at 1pm on a Friday, the T-24 EUA will run at 1pm on Thursday.

A little strange if you got an upgrade within the T-24 because it should have already run. Not sure how SDC works with EUA

That's IT! I was unaware of t T-24 upgrade. I checked the exact time of the email notice and it was within 3 minutes of T-24.

Since the upgradeable flight was the second leg of the ITN, it was actually confirmed about 25 hours before flight time. For SDC only the first segment must be within the 24 hour window.

Thanks very much. This now makes complete sense.

I will have to look and see if the T-24 is a published phenomenon!

EUA now runs "on demand" instead of at scheduled intervals. When CO makes upgrade space available, the next person on the list should be upgraded right away rather than waiting until a scheduled EUA run.

I believe this is only within the 24-hour/OLCI window. Outside of that isn't it still at 24-hour intervals from the departure time?

I think every advance (> 24h) EUA I've received this year (a small handful) has been right around the time of departure, i.e., at 24h intervals. Small sample set, but doesn't refute your assertion.

Oddly enough in May when I went to NAS...I got upgraded both segments right at the 24 Hour Mark doing OCLI as a Platinum on an L Fare, Miss USA18DCA was on an N Fare however I got upgraded before her which is odd considering N should clear before L in terms of EUA but since this was a check-in upgrade run...Oh well I don't bother to understand how CO's IT works because you know how these boys back in Houston are peculiar about this. :D