Same Day Confirm onto a later flight?
First time ever flying AC (Be Gentle!)
I booked a MSP-YYZ-BOM flight using my UA miles in Business (I Class). The issue is that my MSP-YYZ flight leaves at 6.30 AM in the morning and leaves with me a hellish 12h layover in YYZ. Since I am booked in First/Business Class, I am wondering if AC allows me to check for available space a day before and confirm into the later flight that leaves MSP at around 4 PM thereby minimizing my layover. Looking at other threads I think its possible to confirm if there is space available but I am not sure how this will work if I am using miles ticketed through UA.
Advice greatly appreciated.