In the lunisolar calender, there is another kind, which differs from the former in the way that the months are named. When a full moon, instead of new moon, occurs before sunrise on a day, then that day is said to be the first day of the lunar month.
In this case, the end of the lunar month will coincide with a full moon, which is called the purnimanta mana or full moon ending reckoning, as against the amanta mana or new moon ending reckoning that was used before. Due to this, the definition leads to a number of complications, which includes the first paksha of the month will be krishna and the second will be shukla. Also, the new year is still on the first day of the Chaitra shukla paksha.
The next pakshas will be the Vaishakha krishna, Vaishakha shukla, Jyaishtha krishna and so on, till Phalguna krishna, Phalguna shukla and Chaitra krishna, which is now the last paksha of the year. The shukla paksha of a given month, say Chaitra, comprises the same actual days in both systems, as can be deduces from a careful analysis of the rules. However, the Chaitra krishna pakshas defined by the two systems will be on different days, since the Chaitra krishna paksha precedes the Chaitra shukla paksha is the purnimanta system but follows it in the amanta system.
Though the regular months are defined by the full moon, the adhika and kshaya lunar months are still defined by the new moon. That is, even if the purnimanta system is followed, adhika or kshaya months will start with the first sunrise after the new moon, and end with the new moon. The adhika month will therefore get sandwiched between the two pakshas of the nija months. For example, a Shravana adhika masa will be inserted as nija Shravana krishna paksha, adhika Shravana shukla paksha, adhika Shravana krishna paksha, and nija Shravana shukla paksha after which Bhadrapada krishna paksha will come as usual.
If there is an adhika Chaitra, then it will follow the nija, Chaitra krishna paksha, at the end of the year. Only with the nija, Chaitra shukla paksha, will the new year start. The only exception is when it is followed by a kshaya, and that will be mentioned later. The kshaya month is more complicated. If in the amanta system there is a Pausha-Magha kshaya, then in the purnimanta system there will be the following pakshas, Pausha krishna paksha, Pausha-Maagha kshaya shukla paksha, Maagha-Phaalguna kshaya krishna paksha and a Phalguna shukla paksha.
In a special kshaya case where an adhika masa precedes a kshaya masa gets even more convoluted. First, we should remember that the Ashvayuja shukla paksha is the same in both the systems. After this come the following pakshas, nija Kartika krishna paksha, adhika Kartika shukla paksha, adhika Kartika krishna paksha, Kartika-Magashirsha kshaya shukla paksha, Magashirsha-Pausha kshaya krishna paksha, Pausha shukla paksha, followed by the Magha krishna paksha etc as usual.
The considerations for the new year depends upon if there is a Chaitra-Vaishakha kshaya shukla paksha, if an adhika Chaitra precedes it, then the adhika Chaitra shukla paksha starts the new year, and if not, then the kshaya shukla paksha starts the new year. If there is a Phalguna-Chaitra kshaya shukla paksha then it starts the new year. It must be noted, however, that none of these above complications can cause a change in the day of religious observances.
Since only the name of the krishna pakshas of the months will change in the two systems, the festivals which fall on the krishna paksha will be defined by the appropriate changed name. That is, the Mahashivaratri, defined in the amanta mana to be observed on the fourteenth of the Magha krishna paksha will now, in the purnimanta mana, be defined by the Phalguna krishna paksha.