"Overnight flight" refers to a journey by plane that takes place during the night, when you board the plane in the evening and arrive at your destination in the morning. Full definition
Don't count on airlines carrying blankets for every passenger — even on overnight flights. (ordinarytraveler.com)
And it's especially an issue for overnight flights and time changes. (simplyquinoa.com)
It's bad enough on a two hour domestic flight, but amplified even more when you see the front of the cabin settling into their lie flat seats for a long overnight flight. (pointsmilesandmore.com)