Riddle me this?? Daylight savings time

[GoFish]

Anyone good at math?
I’m giving family a ride to the airport this Saturday (Nov 4th) evening, their flight is at 01:40 am PST on Sunday (Nov 5th) The clocks fall back one hour at 02:00 am PST on Sunday (Nov 5th). In effect it will be 01:40 am twice exactly 60 minutes apart.
Which 01:40am is the flight at? The 1st or the 2nd time?

Ps, the flight itinerary makes no mention of this nor does it denote PST or PDT