Hi,
So just a lowly Silver, going on an Int'l trip with a transcon before.

How does the 24 hour timing thing work. Origin departure starts the 24hour clock.

So for instance Lv SFO 8AM Lv EWR 6pm Friday

I do the upgrade request 8am Thursday or 1201am thurs??

is that for both legs, or do I have to do the connecting segment 6pm Thurs?

Needing to learn the ropes, thanks in advance