When you are in the Eastern Time Zone, but you think you are in the Western Time Zone
Dude: I hate New Hampshire, too cold outside - When do you Depart?
Pilot: 17:00 well 18:00 your time
Dude: Oh - Where are you?
Dude: as in Georgia? The same Georgia that touches the Atlantic? What are you in the Western burbs of Atlanta?
Pilot: Shut-up I'm in Atlanta Time