Pradosham and its significance

Significance of the Pradosham
Everyday, twilight time (approx 5-6 PM) is known as the Dina (daily) Pradosha Kaalam, and the Pradosham on the 13th lunar day (Shukla/Krishna Paksha Trayodashi) is very special for the worship of Lord Shiva. Even more special is a Pradosham on a saturday, called Shani Pradosham. "Dosham" is the effect of a sin, and PraDosham means relief from this. That is, the devout who worship Lord Shiva during this time are liberated from Karmic effects, and this finally leads to Moksham, the ultimate liberation.

What has Shiva got to do with Pradosham?
The Guru Charitra, the book on Lord Dattatreya, explains this.
During the Samudra Manthanam, the churning of the sea in search of Amritham, the ambrosia of immortality, pleasant things happened, like the emergence of Lakshmi, Kamadhenu, etc. However, along with these came the dreaded Halahala poison, which frightened away the Devas and Asuras. To save the universe from the devastating poison, everyone approached Lord Shiva for help. Since He was in meditation, they didn't disturb Him, and instead fasted on that day (Ekadashi) and finished the fast on the next day (Dwadashi), after which the Lord emerged from meditation, pleased by the prayers. Shiva then Himself took all the venom to save the world, however Parvathi stopped the venom in His throat itself, thus saving the Lord. After this is over, on Trayodashi day, all the Devas worship Him in gratitude. So, Shiva is in a very happy state and it is very beneficial for us to worship Him at this Pradosham time. Also, worshipping Him during Pradosham is very special as all the Devas are also there, worshipping Him at the same time!

Pradosha Vratham:
On Trayodashi day, it is very auspicious to fast from dawn to dusk, that is until the Pradosha Pooja is done. Sage Shandilya has also brought out the significance of the Vrata by prescribing this to a young prince, who then follows it and goes on to destroy his enemies.
Thus, going to a temple and worshipping the Lord with a Vilva mala (garland of leaves from the Wood apple tree) during Pradosham bestows abundant blessings to the devotees.

I was fortunate to have visited the famous two-millennia old Shiva temple in Perur, Coimbatore during Pradosham last week :-)