The phrase describes periods when the boundary between the living world and the realm of spirits is believed to be particularly permeable. Folklore and various belief systems posit that during these times, interaction with otherworldly entities is more accessible. Examples often cited include specific dates or festivals in various cultures.
The concept has significant importance in cultural traditions, often leading to heightened spiritual observances, rituals, and commemorations of ancestors. Historically, societies have tailored practices to respect and manage this perceived increased interaction, seeking blessings, guidance, or protection from the spiritual realm. This belief offers comfort to some, providing a framework for understanding death and a connection to those who have passed.