The Witching...Months?

This is a great backdrop for a novel, or a seance. There seems to be a pervasive idea across various cultures about the months between September to November to be a time when the veil between the living world and the spiritual world is at its thinnest. I feel there must be something to this because of the various cultures that did believe this without having a connection to one another. Any thoughts?

Samhain - November 1^st but celebrations start at sunset on October 31st, on Samhain Eve. Dates back to the ancient Celts who lived 2,000 years ago. On October 31st, the fires within the home are extinguished, families do a good "fall" cleaning to clear out the old and make way for the new.

Villages would begin the formal ceremonies of Samhain by lighting a giant bonfire. The people would gather around the fire to burn crops and animals as sacrifices to the Celtic deities.

During the celebration, the Celts wore costumes, and danced around the bonfire. These costumes were adorned for three primary reasons.

1.    Honor the dead who were allowed to rise from the Otherworld. The Celts believed that souls were set free from the land of the dead during the eve of Samhain.

2.    Some souls were feared as they would return to the physical world and destroy crops, hide livestock or 'haunt' the living who may have done them wrong. The second reason for these traditional costumes was to hide from these malevolent spirits to escape their trickery.

3.    Honor the Celtic Gods and Goddesses of the harvest, fields and flocks.

Day of the dead - November 1st. Aztec tradition from 3,000 years ago. During the days of the Dead (October 31^st to November 1^st/2^nd), some believe that the souls of the departed return to earth to visit with and to provide council or give advice to family and loved ones.  There is a belief that this is true every day, but that November 2nd is the day set aside to remember and honor those who have past.

Chuseok - late September or early October. celebrated to give thanks to dead ancestors for an abundant harvest.

Pitru Paksha (Fortnight of the Ancestors) - Usually between September and October. This Hindu tradition is a fifteen-day period during the Hindu month of Ashwin where a person remembers their ancestors, particularly through offerings of food. The Hindu month of Ashwin is the seventh month of the lunisolar Hindu calendar.