Kalashtami, which is also called as Kala Ashtami, is celebrate every month during Ashtami Tithi of Krishna Paksha. Devotees of God Bhairav G keep fast and worship Him on all Kalashtami days throughout the year.
The most significant and important Kalashtami, which is known as Kalabhairav Jayanti, falls in the month of Margah shirsha according to North Indian, Purnima to Purnima, lunar month calendar while Kalabhairav Jayanti falls in the month of Kartik in South Indian, Amavasya to Amavasya, lunar month calendar. However in both calendars Kalabhairav Jayanti is on the same day. It is believed that Lord Shiva was appeared in form of Bhairav on the same day.
Kalabhairav Jayanti is also Celebrate as Bhairav Ashtami.