No grains should be consumed during Janmashtami fasting until the fast is broken on next day after Sunrise. All rules followed during Ekadashi fasting should be followed during Janmashtami fasting also.
Parana which means breaking the fast should be done at an appropriate time. For Krishna Janmashtami fasting, Parana is done on next day after Sunrise when Ashtami Tithi and Rohini Nakshatra are over. If Ashtami Tithi and Rohini Nakshatra do not get over before Sunset then fast can be broken during the daytime when either Ashtami Tithi or Rohini Nakshatra is over. When neither Ashtami Tithi nor Rohini Nakshatra is over before Sunset or even Hindu Midnight (also known as Nishita Time) one should wait to get them over before breaking the fast.
Depending on end timing of Ashtami Tithi and Rohini Nakshatra fasting on Krishna Janmashtami might continue for two complete days. Devotees who are not able to follow two days fasting might break the fast on next day after Sunrise. It has been suggested by Hindu religious text Dharmasindhu.
Krishna Janmashtami is also known as Krishnashtami, Gokulashtami, Ashtami Rohini, Srikrishna Jayanti and Sree Jayanthi.
Nirjal Fast or Upavasa for Lord KrishnaArdent followers of Lord Krishna celebrate Janmashtami by keeping 'Nirjal' fasts. This kind of fasting involves not having even a single drop of water during the entire day. People feel keeping nirjal or waterless fasts will help them get closer to God. Devotees also keep 'Phalahar Vrat' having milk and fruits during the fast. Devotees observe strict discipline while fasting. They refrain from having cereals and salt on the day of the festival . They also feel keeping such fast is the only thing that they can offer God. Fasting is accompanied by singing of devotional songs and mantra chanting.