I think the closer you are to the equator, the shorter the sunsets. Of course, at the poles, the sun doesn't seem to set in their respective summers. We live in Hobart at about 42 degrees south, and our summer sunsets (and consequently) days are quite long compared with, say, Far North Queensland.

I use my compass more in the city than in rural areas. I also use it during cloudy days in the woods.
I have only cycled compass bearing once, traversing a trail above the treeline, over a foggy mountain in Spain.

Yes, extremely variable. I guess I should have been more specific. That approximation seems to work around the continental USA. Obviously, it didn't work on the Alaska Highway, where the sun just sort of goes around in circles. But give it a try and see if it works for you.

On flat terrain it really isn't that useful, as the sun will set pretty much the same time as the night before. But it is useful in the mountains, when the sun may go behind a big ridge an hour or two earlier than "sunset".

Me too, carry a small compass I use when backpacking, it's about 1.5" x 2", carry in top tube bag, used it many times.

on a Boat it wont tell you where the Bottom is going to come up and Bite you, and run aground, or rip ahole in the hull. for that you need to read the Charts.

On a Bike You can always stop and ask the Locals.

No maps, compass, north star, sextant, sun shade, watch with hour hand, gps, asking the locals, etc are needed if you are navigating in a moslem area. Moslem's graves in islamic countries always point in the direction of Mecca, graves in a general area north of mecca then would point you in southern direction and so on and so forth. You just have to find a grave site nearby ..... :-)

I look at the sun. And use a map and road signs. I'm in New England, not wicked wilderness.

I carry a map and compass.Just got used to using them.

I always used a map and compass when backpacking or just hiking, so when I started touring I just automatically took one along. I realized about halfway across the US that I really didn't need one for road touring and I mailed it and the GPS home. A very general idea of where north is is sufficient and I find that easy to maintain by the sun and various land features such as bodies of water and mountain ranges.

I still carry a compass for hiking or off road bike touring.

Edit: Correction... I guess I actually do have a compass along in the form of a compass app on my phone, but I have yet to use it on tour.

Compasses dont always work well, if there is high metal quantities in the ground, you may get bad readings.