The evening sun popularly called the sunset. Sunset does not mean the sun is going to sleep, it means it has given more attention to other part of the world and lesser to your locality
Sunset doesn't mean the sun is less hot or weak it has transfered more energy to the part of the earth where it is called sunrise
The fact that you can look at the sun directly when it is setting but cannot look at it directly during midday amazes me and leaves me know that nature is a blessing.
I Love the sunset and sunset photography