In the lunar cycle there are so-called satanic lunar days (days), which are considered extremely unfavorable, critical or upheaval. They are also called the days of the hekate. According to legend, once the devil planned to destroy the moon in order to make people vulnerable. Hecate was supposed to fulfill the plan. But the Wind intervened and limited the possibilities of the goddess to lunar days, making her actions predictable. However, every time the Moon changes phase, the formidable Hecate tries to get out of the prison, and her destructive energy negatively affects people.
Believe the legends or not - it's up to you, but the fact remains: on the days of the change of the lunar phases, people really do not feel very good.