If we are on a vacation and alone the sunset normally gave us the feeling of a little bit sadness. It is because as the sun stimulates the secretion of happy hormones. Sunset is not different from what we feel during rainy season.
Seasonal Affective Disorder also known as "SAD" usually occurs during rainy season and winter ,it is because during these seasons the sun is behind the clouds.
As a nurse I usually encourage our patients especially those who gave birth to have a morning sunlight to avoid the occurrence of post-partum depression.
All photos are mine.