Batuk Bhairav Jayanti (बटुक भैरव जयंती)
According to Indian mythology, the kaal bhairav ashtami is celebrated on the astami of Krishna paksha {eight day of waning moon} of margshirsha month of Hindu calendar. On this day, lord Shiva appeared in the form of Bhairav and worshipping of the lord Shiva in this form helps the worshiper to become free from all his bad karmas and sins. The kaal bahirav ashtami is also  known as kaalaashtami and fast is observed by the devotees on this day. If the devotees worship bahiraavnath with full devotion and faith, his all wishes get fulfilled.
Lord bhairavnath has the knowledge of all mantra- tantra. According to shiv purana he is known as the rudra avatar, another form of lord Shiva. He is the creator and supporter of the world. His devotees are always blessed by him and get relief from all the sufferings of life. The person gets bestowed by the bhairavnaths blessings if offer prayers on kaalashtami.
Bhairavastami puja vidhi:
The puja of kaal bhairav has to be performing cautiously with all rituals and purity of thoughts. First place the bhairav idol, painting, or yantra in puja place. Then lord ganesha is worship frst and then prayers are offer to bhairav nath. Jaagran has to be performing as the part of puja. Bhairav katha is to be reciting during the puja followed by the bahairav nath aarti.
The vehicle of bhairavnath is the dog. So feeding a black dog helps in getting the blessings of the bhairav nath.
Importance of puja: 
The one who performs the puja and observes the fast on the kaalashtami gets free from all his sins, sufferings, and fears. One should take bath in a holy river early in the morning and perform tarpan and shraadh for the ancestors followed by the bhirav nath puja. This helps the devotees to get rid of all the sins of their previous life. It also helps in removing the fear of ghosts, evilspirits etc.
This puja brings in courage and dedication in the work of devotee and protects him from all diseases.
Significance of puja:
On this day, goddess kali is also worship along with kaal bhairav as we do in navratras. This puja helps attaining the peace and harmony in life. The wealth and health of family is also maintained by the puja. Reading bhairav chalisa, bhairav tantroktam, bayuk bhairav kawach, kaal bhairav strota, batuk bhairav brahma kawach etc helps in getting the relief from all kind of difficulties and hurdles coming through the success in life. The person gets free from all ill-starred deeds and malefic effects of planets. The puja continues for whole night with the bhajans and kirtans and stories of lord Shiva and Parvati.
Kaal bhairav puja matra:
Bhairavardhya grihanesh bheemroopaavyayaanagh|
Aneenaardhyapradanen tushto bhav Shiva priyaa||
Sahastraakshishirobaaho sahastrachranajar|
Grihanaardhyam Bhairavedam spushyam parmeshvar||
Pushpanjalim grihanesh vardo bhava bhirava|
Purardhya grihanedam sapushyapam yaatnaapah||