Koyomi is a term that can refer to a calendar or a system of timekeeping in Japanese culture. It is often associated with the traditional lunar calendar, which has been used for centuries to mark festivals, agricultural activities, and seasonal changes. The Koyomi helps people organize their lives according to the cycles of nature. In modern contexts, Koyomi can also refer to specific characters in Japanese media, such as Koyomi Araragi from the Monogatari series. This character is known for his interactions with various supernatural beings and his journey through complex relationships, making him a central figure in the narrative.