You know, there are phrases like: the golden hour, the yellow hour...
Our sleep / awake rhythm is controlled by the color of sunlight. In the morning we have the blue hour which activate insight body drugs who make us awake and stand up. In the evening the golden hour gives us the feeling of feeling satisfied and the sleeping hormon Melatonin will be distributed and makes us ready for a healthy sleep....
In December, i made a walk with my wife Susan in the afternoon along the Danube, the biggest river in Austria. The days are very short in this time, the sunset is nearly 4 pm. If you look at these pictures, you will sleep well next night :))