Chapter 63 of 76 · Vayaviya Samhita · Overall chapter 451 of 464
Nitya and Naimittika
Upamanyu catalogues the full calendar of periodic (naimittika) observances tied to specific months and nakshatras - from the Pousha nirajana through the Chaitra dola festival to the Margashirsha ghee-bath - then describes the graduated afterlife journey through Shiva's and other deities' worlds that results from performing these rites fully, by half, or only partially.
Upamanyu said
Next I will tell you the nitya and naimittika rules, as described along the path of Shiva's texts, for followers of Shiva's ashrama. They are performed every month in both fortnights, on the eighth and fourteenth and the respective parva days. They are also done when the ayanas change, at vishuva sankranti, and especially at an eclipse. At these times a great puja is done as capacity allows. Every month he follows the rules and prepares brahmakurcha. After fasting, he bathes Shiva and drinks what is left. If a person has committed a great sin like killing a brahmana, drinking brahmakurcha saves him; nothing else is better. In Pousha, when Pushya is in the ascendant, the lord's lamp-waving is done. In Magha, when the star Magha is in the ascendant, he gives ghee and a blanket. In Phalguna, when Uttara Phalguni is in the ascendant, he begins a great festival. In Chaitra, when Chitra is in the ascendant and on the full moon, he holds the swing festival. In Vaishakha, when Vishakha is in the ascendant, he makes a great temple of flowers. In Jyeshtha, when Mula is in the ascendant, he offers a pot of cold water. In Ashadha, when Uttara Ashadha is in the ascendant, the pavitra is put on. In Shravana natural mandalas are drawn. In Proshthapada, when Shravishtha is in the ascendant, this is done too. In Proshthapada, when Purva Ashadha is in the ascendant, water games are arranged. In Ashvayujya, when Shatabhisha is in the ascendant, sweet milk rice and newly harvested rice are given and fire rites done. In Kartika, with the Krittika conjunction, a thousand lamps are given. In Margashirsha, when Ardra is in the ascendant, Shiva is bathed with ghee. Those unable to do these at these times go to a place where a great worship is being held and worship there. Such auspicious rites of bathing, worship, japa, meditation, oblations and gifts are especially praised when the mind is covered with dejection, when there is evil conduct, when one has seen a nightmare or evil omen, or faces a great difficulty. Such tasks, which have qualities, should be preceded by purashcharana. If Shiva's fire goes out, it must be kindled again.
A person constantly engaged in pursuing Sharva's dharma in this way is granted liberation by Maheshvara within a single life. One who does other nitya and naimittika rites goes to Shrikantha's divine abode and for hundreds of crores of kalpas enjoys great pleasures there. When he is dislodged, he goes to the worlds of Uma, Kumara, Vishnu, Brahma and Rudra, lives there a long time enjoying the pleasures described, and then rises beyond these five regions. With knowledge of Shrikantha he goes to Shiva's city. A person who does half the number of rites goes up and down twice, and only after that gains knowledge and sayujya with Shiva. A person who does only a quarter of the prescribed rites heads upward on giving up his body, beyond two worlds, the end of the cosmic egg and the unmanifest. He reaches the worlds of Purusha and Rudra, husband of the mountain king's daughter, and for many thousands of yugas enjoys many pleasures. When his merit is spent he is born on earth in a great line, but through his former impressions the very radiant one gives up the Pashu's dharma and is devoted to Shiva's dharma. By the power of that dharma he meditates and goes to Shiva's city. Having enjoyed many pleasures there, he goes to Vidyeshvara's world and enjoys many pleasures with the Vidyeshvaras. After that he returns once, inside the cosmic egg or outside it, gains knowledge of Shiva and supreme devotion, and by resorting to Shiva's dharma does not return again. As a person's mind can be addicted to material things, so a person can be extremely devoted to Shiva, and in that case, whether he follows Shiva's dharma or not, he will be liberated. He may return once, twice or thrice, but in the end will not return. He then becomes a Chakravarti, with a rite for following Shiva's dharma. So by whatever reason possible one should take refuge in Shiva. A person who wants his own welfare should turn his mind to Shiva's dharma and work at it. But we will not try to force anyone by any means. Our nature is such that force and excessive debate do not appeal to us. The dharma appeals to others through the power of their merit and impressions, and because of those impressions they do not suffer from impurities. Because of these natural qualities they forget nothing. So a person who wants welfare should follow Shiva's dharma.
Retold in our own words from Bibek Debroy's English translation of the Shiva Purana (Penguin Classics). Names, numbers and the order of events follow the source.