The Pradosha Vrata is observed in the evening twilight on the thirteenth day of each lunar fortnight. The Hindus who are especially engaged in the motivated type of worship, selects this Vrata as this is the time when god is in his most pleasant aspect. The Pradosha Vrata is based on the mystic psychology of the ancient sages who experienced the evening twilight to be the most efficacious in appeasing the deity.

Pradosha is the worship of Lord Shiva and Parvati when they both are in an extremely propitious mood. The ancient story behind the Vrata is like this- the Gods when repeatedly being defeated in the wars with demons, came to Lord Shiva to bless them with a leader for their celestial emcees. The gods came to Shiva at the sunset on the thirteenth day of lunar fortnight and found him in the blissful company with his consort, Goddess Parvati. When the gods glorified the Lord with sacred hymns, he was so satisfied that immediately granted their request. From then on this moment is considered extremely auspicious.

The Skanda Purana gives hint of another story of how Shandilya Muni prescribed this Vrata to a Brahman lady. The lady came to the sage with two boys, one her son suchivrata and the other an orphan prince, Dharmagupta. Dharmagupta`s father was killed in a battle and the enemies conquered the kingdom. Shandilya Muni asked the woman and the two boys to perform the Pradosha Vrata with great devotion. After four months in eighth Pradosha, Suchivrata obtained a pot of nectar and drank the divine ambrosia. Prince Dharmagupta won the hand of a celestial princess. Lord Shiva ordered celestial king himself to help Dharmagupta to win back his kingdom and defeat his enemies. Then Dharmagupta attained the Lord`s supreme abode. Thus by performing this Vrata they can please the Lord Shiva very easily.

To perform the Vrata, one has to fast on the day and keep vigil at night after the fasting is over. The worshipper first performs a preliminary worship after taking the bath one hour before sunset and worships Lord shiva together with his family i.e. with Parvati, Ganesha, Skanda and Nandi. After worshipping of Lord Ganesha, Shiva is evoked in a special `Kalasha` placed on a square Mandala with a lotus on it and spread over with Darbha grass. When the formal worship is completed, a Pradosha story is read and heard by the devotees. This is followed by a recitation of Maha Mrityunjaya Mantra for 108 times. At the end, the holy water of the sacred Kalasha is shared, the sacred ash is applied to the forehead and the water, which was used to bathe the lord, is drunk. At the conclusion a gift of a pot, a cloth and an image of Lord Shiva is given to the Brahmin.

There are five types of Pradosh:
1. NITYA Pradosh- The evening time on all days, between just 3 ghatis (72 minutes) before sunset and the time when the stars rise or become visible in the sky.

2. Paksha Pradosh- Sandhya (evening) time of Shukla Paksha Chaturthi (4th Lunar day after New Moon) every month.

3. Maasa Pradosh- Sandhya Krishna Paksha Trayodashi (13th Lunar day after Full Moon) every month.

4. Maha Pradosh- Sandhya time of Krishna Paksha Trayodashi which falls on a Saturday.

5. Pralaya Pradosh- The time when the entire universe gets annihilated of merged with Lord Shiva. Pradosh Vrat is observed on every 13th Lunar day after full and new Moon, by the wife and husband jointly with the hope of being free from, miseries or for gaining material prosperity.

They should bath early in the morning, adore Lord Shiva, and fast during the day, and after bath in the Evening, perform Pujas to Lord Shiva and his consort Pravati with the offerings of flowers and Naivedyams.