Am I the only one thinking there is something strange with the numbers in the screen capture ? the time is 4:42, the plane lands at 5:23, it's a 33 minutes drive... so you should leave in 8 minutes, not in 18 minutes.
It's correct. The numbers won't match your back-of-the-envelope calculations because it's a tad more involved than you're assuming. Among other factors, there's additional time for the plane to debark and for passengers to make it to baggage claim. You don't want to arrive at the airport just as the plane is landing. Plus, I'm not sure how Sean edited that video together when he did the screen capture.
Props for noticing tho ;)
That makes sense; however as a visitor of this page I don't know about all these details so I might think it's a possible error and I shouldn't trust your app. Basically there is a small risk to lose potential users here. I suggest choosing another example with a calculated vs intuitive time gap different from exactly 10 minutes.
I did a screen recording of the app as it tracked a real flight and during the editing process I made sure to stay true to the times.