Describing late afternoon by the sun's position in the sky?

Up. And sometimes sort of sideways.

ETA: I know you were hoping for better, but I didn't want you to be discouraged by not having answers. Someone who knows will be along shortly.

ETA2: You reminded me of a lovely thing I read oh about 50 years ago, where Rudyard Kipling describes some children out very-early-morning and says the turf dripped like rain, and the shadows ran the wrong way, like evening in the East. (or something like that. Will look it up after coffee). It stayed with me because it was the first time I realised how big the Earth must be.

Shadows are excellent.

You could always go outside and observe the light and shadows at the times you're writing about.

If that's not an option, Google or YouTube for timelapse videos of light or shadows throughout the day.

Try this:

http://www.suncalc.net

You can set the position in the world and the time, and it will show you the location of the sun in the sky. It takes a little while to figure out how it works but once you do it's pretty nifty. It may help you.

The most memorable things about late afternoon/sunset for me are the heat radiating from every dark surface, and the way the sun is low enough to get in your face every time you turn around. And, especially in summer, the actual sunset is so quick.

When you are looking straight ahead and the sun is in your eyes you know it's getting late.
When you are walking down a hill and your path goes into the shade and you stop feeling the heat of the day, you know it's getting late.
If you walk down that same hill and turn a corner and now see into the valley, and it is all in shade yet the tops of the hills are bright with sun, you know it's getting late.
When you're walking along a long, straight, dusty Kansas road and you see your shadow many yards ahead of you but you still feel the warmth of the sun on your neck, you know it's getting late.

The position of the sun changes from day to day, but also with the seasons. Sometimes, it's *here*, and sometimes, it's *way over there*. In the Northern Hemisphere, it's usually more southerly, with a lower arc across the sky, during the winter. During the summer, it's usually more northerly, with a higher arc across the sky.

The quality of the light is very different in late afternoon than at other times of day. It's a warmer, richer color, especially in the summer. If you're out at sunset, and there are clouds (or mountains) near where the sun is setting, you can actually see the sun move at a fairly rapid pace. The sun moves just as fast high in the sky at noon, but with nothing stable to really compare it to, you can't track its progress. Same thing with the sunrise: often times, the sun will rise, and will be a darker color, with cool light, and everything bathed in pastels, and after it rises a smidge, it gets its usual brilliance. This is because it has less atmosphere to travel through. If it's a very weather-y kind of day, with lots of particles in the sky, it also has an effect on the nature of the light.

So-- go outside. Watch a sunset. Watch a sunrise. Notice how sometimes, there's a little gap between the horizon and the rim of the visible sun. Pay attention to the quality of the light. And wait a week, or a month, or a couple of months, and do it again, and see how it's very different, depending on season and weather.

The way I remember it is that Japan in sometimes known as "land of the rising sun" and is in the East (relative to the UK/Europe - other parts of the world may need to think of other ways to remember it). The sun rises in the East and sets in the West. It forms an arc in the sky, reaching it's highest point at noon (which isn't exactly 12:00 as it varies with location).

It varies by time of year and location and can get complicated but you can find websites that show it as a diagram and it's a lot easier to explain visually. http://physics.weber.edu/schroeder/ua/sunandseasons.html

Shadows always point away from the sun, and the higher the sun is in the sky, the shorter the shadow. If the sun's directly overhead (this only happens in the tropics*) then your shadow's like a puddle under your feet. The lower the sun is in the sky, the longer the shadow.

*i.e. places located between the Tropic of Cancer and the Tropic of Capricorn

You do not need to go into that much detail though for most stories, in fact, it's likely to bog the reader down in too many intricate details, especially as very few people know how to make a sundial or tell the exact time of day from the sun's position so it won't be easy to relate to. If you do need this info, there are websites that can calculate stuff like this. For most stories, things like "the shadows started to grow long" or "the sun was low in the sky" would indicate late afternoon, and that would be all that you need.

Early morning light has more of the blue light frequencies and evening light has more of the red. This is to do with the way the light is scattered through the atmosphere. The sun, of course, always emits the same frequencies (i.e. all of them and very intensely). The sky can appear red in the morning, but the light that falls on things still has a slight blueish tinge. The folk wisdom over here (UK) is that a red sky in the morning is a sign that the weather's not going to be very good, as in the saying "red sky in the morning, shepherd's warning; red sky at night, shepherd's delight." (Though as the weather over here's very often bad, it brings to mind a Scottish saying: "if you can see the tops of the mountains, it's going to rain. If you can't see the tops of the mountains, it's already raining" ) But when it comes to descriptions in books, if you describe for example the early morning light having a slight blueish tinge, or the reds, oranges and golds of the late afternoon light it can add a really nice touch.

One of my WIPs is set 40,000 years ago and the only indication of time of day is what the sun's doing so my MC's often making observations about the sun, e.g. "the sun's high in the sky" = around noon. He doesn't think in modern terms of times of day (noon, four o'clock in the afternoon, etc), the only time reference is the position of the sun. i.e. it's not: "the sun's high in the sky, it must be noon" just "the sun's high in the sky" - the reader can infer that it's around noon/middle of the day. Sun getting higher in the sky = morning; sun getting lower in the sky = afternoon. Most stories won't need much more detail than this, and you can relate the info in the way that would make sense to your POV character.

You can directly observe what the shadows are doing relative to the sun. In a dark room, place a tall object (representing a character or building) on a table (the Earth) and use a torch* (the sun) and place the torch where the sun would be in the sky, and you can see exactly where the shadow of the object falls. You can also move the torch in the sun's path and see how the shadow changes. This works best when there's no other source of light besides the torch, as other sources of light will make other shadows.

*flashlight in USA

Where is your story set and what season of the year is it?

Another trick you can do with a stick in the ground is determine direction. Mark the tip of the shadow from the sun, drink a few beers*, then mark it again. Draw a line between the two. That is the east-west line. The first mark is the west direction, and the second the east.

*you can omit the beers, but we're talking 10-15 minutes wait time

Recommendation: go outside in the late afternoon and observe the shadows and the quality of light for yourself. Do this repeatedly and take notes. If you are in a temperate location you will find there are significant seasonal differences: the golden glow of summer evenings is very different from the wan, pallid twilight of winter. The precise angle of the sun, and its precise location along the horizon, will also vary greatly across the year. There are roads it's difficult for me to drive on at certain times on a few days of the year because they put the sun directly in my eyes too low for the visor on the windshield to be of any use. That, too, is one of the things that happens in late afternoon!

If you don't want to take the time to make your own observations across the year, or if you're writing about a location that's different from where you are, YouTube is your friend.