On Wednesday, April 11, 2018 at 12:43:53 AM UTC+1, palsing wrote:
On Tuesday, April 10, 2018 at 1:50:17 PM UTC-7, Gerald Kelleher wrote:

https://www.timeanddate.com/sun/kenya/nairobi

Very nice page, Gerald, lots of plain, simple facts, and all the facts are spot-on correct. Good find on your part.

I invite you to scroll down to the bottom right-hand side of that page and click this link... What is twilight, dawn, and dusk?

https://www.timeanddate.com/astronom...-twilight.html


This was covered a few days ago where Roland bases his sunset to sunrise on the local horizon which may only be 10 miles in diameter hence different types of twilight in that format are invalid.

There are two different types of twilight - daily twilight and the altogether different twilight happening presently at the South Pole as that latitudes turns away from the Sun -

https://www.usap.gov/videoclipsandmaps/spwebcam.cfm

( why the people responsible for the webcam are intentionally screwing up is anyone's guess )

The roughly 6 week polar twilight before polar night sets in and the surface rotation behind it is obscured by celestial sphere descriptions.