Kalashtami, which is also known as Kala
Ashtami, is observed every month during
Ashtami Tithi of Krishna Paksha. Devotees
of Lord Bhairav keep fast and worship Him on
all Kalashtami days in the year.
The most significant Kalashtami, which is
known as Kalabhairav Jayanti, falls in the
month of Margashirsha 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
both calendars observe Kalabhairav Jayanti on
the same day. It is believed that Lord
Shiva was appeared in form of Bhairav on the same day.
Kalabhairav Jayanti is also known as Bhairav
Ashtami.
It should be noted that Kalashtami fasting
might be observed on Saptami Tithi. According
to religious text Vratraj Kalashtami fasting
should be observed on the day when Ashtami
Tithi prevails during night. Accordingly
DrikPanchang makes sure that Ashtami should
prevail at least for one Ghati after Pradosh
while selecting fasting day for Kalashtami.
Otherwise Kalashtami fasting day is moved to
previous day when Ashtami Tithi is more likely
to prevail during night
