Steven and Lapis are seen blasting off during the day.
By the time they’re flying over the trees, it’s about sunset.
Then, they finally reach Manhattan, New York by nightfall. (You can tell because you can see the Empire State Building)
By now, we know that Beach City is located in Delmarva – which is actually Maryland, which has the Delmarva Peninsula.
Probably close to here if you ask me.
Ronaldo says that Delmarvacon is held in Charm City, aka Baltimore; he also says it’s not too far of a drive, so I’m gonna guess Beach City is close to irl Ocean City.
The distance between Ocean City, MD and Manhattan, NY is 180 flight-miles.
A jet plane can take 2 hrs 45 minutes to go that distance. However, Lapis is obviously going slow and steady, otherwise Steven would be flying off her back.
So, Steven has been flying on Lapis’s back for something close to 5 hours, probably.