Hi there, flying T+ (don't know the fare class within T+) from YXU to MCO (via YYZ).

I have a copious amount of eUpgrade credits that are expiring, and R-class availability is looking good for the flights I'm looking at.

Question is, I know that with T+ I can request the eUpgrade...upgrade 2 days prior to flight, but just want to know if that is:

a) 48 hours prior to departure,
b) one second past midnight EST on the date two days prior to the travel date

Or, can I request the u/g now, and have it automatically request the u/g when the 2 day period arises?

Thanks!