I love afternoon shoots and there's nothing better than "Golden Hour". Golden Hour is one hour before sunset when you get all kinds of great warm light as the sun sets.
I have created a table based on this website:
http://aa.usno.navy.mil/data/docs/RS_OneYear.php
Where I've identified all the saturday's for next year and the time that sunset begins and that twilight ends. Typically, this is a 25-30 minute window. If you're looking for the blue sky photo like below, you'll want about 15 minutes or so after sunset, depending on if you're pointing the camera east or west. The blue sky effect will first start in the east and then end up in the west as the sun goes down.
I'll attach a download of all the dates for Macon, but you can use that site to create one for wherever you are. It's great for planning shoots.
If you are a comercial shooter or have a shoot where you need to know a lot about the suns position as it goes down check out this website:
http://www.wide-screen.com/
This site sells software that will allow you to know how long the shadows in your images are going to be so you can plan everything and set everything up before time and just wait on the sun
If you needed really long shadows, this software can tell you exactly when they are.
You got to check out this software. Commerical shooters and Filmmakers both use this softare.
Here's the table I came up with for Macon, Georgia (31210):
Click this link to download the sunset table for Macon.
