The sun will set before 6pm in nearly a quarter of U.S. counties.
It will set between 6 and 7pm in nearly all remaining counties.
The only American trick-or-treaters with sunlight after 7pm will be in parts of West Texas and on Alaska's Aleutian Islands.
Yes, but: Sunset doesn't mean immediate darkness. Twilight typically provides another 20-40 minutes of natural light.
The other side: The waning gibbous Halloween moon won't rise until later in the evening, leaving most would-be vampires without much moonlight.
What's next: Later that night, we shift clocks back one hour. Sunday marks the end of daylight saving time, and the start of much earlier sunsets all around.