Originally Posted by
cmtlatitudes
However shortly after that the flight might show up in my summary with a "hold", but on closer inspection it's either a same day hold only or expires the next day. I say "might" because ~ 50% have followed this pattern and 50% have just disappeared.
The same day holds are temporary while you are finishing the payment/hold checkout pages. They auto-cancel after ~15 minutes if you don't complete the purchase. It's to hold your seats and pricing while you get out your CC and type in the number, etc. If you get to the payment page then jump to your list of upcoming flights you will see the temporary record for that reservation.