I just noticed the sunset border on Flightradar24 maps. I wonder: what are the 4 shades of grey, and why are they relevant? Why not just show one? enter image description here

  • $\begingroup$ I'd like to point out that a question called "3 stages of twilight" is inherently different from "four shades of grey on the FR24 map". First, because I need to know there are stages of twilight and, second, because I need to know that FlightRadar shows the stages of twilight. Then I can find that question and get the information I need. So, instead of calling this question a duplicate, it might have been more relevant to answer "these are the twilight stages" and point to the other question. As WPNSGuy did. $\endgroup$
    – texnic
    Commented Nov 12, 2022 at 19:37

1 Answer 1


Varying levels of daylight, going into night.

This previous question goes into much more detail, and it may indeed be related to the aeronautical definitions as day turns into night.

What are these 3 stages of twilight?

  • $\begingroup$ Upvote for being correct, but there might be a deeper meaning... For example, there is sunset, nautical twilight, etc. that have distinct meanings. Could it be related to these definitions? I don't have time or motivation to research, just throwing it out there... ;) $\endgroup$ Commented Oct 22, 2022 at 16:52
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    $\begingroup$ @Michael Hall - Looking through the FR24 glossary and FAQ, and searching for "day", "night", "grey", "gray", I see nothing related to the varying shades of grey. Of course, I may be just missing it. $\endgroup$
    – WPNSGuy
    Commented Oct 22, 2022 at 17:06

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