Take a look at the picture in Wikipedia’s atcirle. Click on the picture for a bigger version. You can see evening arriving in India and morning arriving over the Rockies.Note the curve of the terminator at the very North and South. This is the effect Berend is talking about. Because of the Earth’s tilt you get all day sun at the North Pole and longer days the further North you go during the Northern summer. (This picture shows daylight in April.) In December the curves would go the other way, narrowing in the North and all day sun in parts of Antarctica.I still think the day/night discussion is a red herring and the reason I gave above is the dead giveaway (along with the amazing glow-in-the-dark Sahara).
<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>