Mbh 13.109.2a

"'Bhishma said, "Listen, O king, to what was sung by the Self-born himself and by accomplishing which a person, without doubt, attains to the highest happiness. That man who fasts on the twelfth day of the moon in the month called Margasirsha and worships Krishna as Kesava for the whole day and night, attains to the merit of the Horse-sacrifice and becomes cleansed of all his sins. He who, after the same manner, fasts on the twelfth day of the moon in the month of Pausha and worships Krishna as Narayana, for the whole day and night, attains to the merits of the Vajapeya sacrifice and the highest success. He who fasts on the twelfth day of the moon in the month of Magha and worships Krishna as Madhava, for the whole day and night, attains to the merits of the Rajasuya sacrifice, and rescues his own race (from misery).[504] He who fasts on the twelfth day of the moon in the month of Phalguna and worships Krishna as Govinda, for the whole day and night, attains to the merit of the Atiratra sacrifice and goes to the region of Soma. He who fasts on the twelfth day of the moon in the month of Chaitra and worships Krishna as Vishnu, for the whole day and night, attains to the merit of the Pundarika sacrifice and proceeds to the region of the deities. By observing a similar fast on the twelfth day of the month of Vaisakha and worshipping Krishna as the slayer of Madhu for the whole day and night, one attains to the merits of the Agnishtoma sacrifice and proceeds to the region of Soma. By observing a fast on the twelfth lunar day in the month of Jyaishtha and worshipping Krishna as him who had (in Vali's sacrifice) covered the universe with three steps of his, one attains to the merits of the Gomedha sacrifice and sports with the Apsaras in great happiness.