The eleventh day
(ekadashi) of the brilliant (waxing) half of the lunar month of Magh
(January–February) is the festival.
This festival, like other eleventh-day observances, is
devoted to the worship of Vishnu, particularly in his avatar as Krishna on this
day.
Most Hindu holidays have specified rituals, which generally include fasting (upavasa) and prayer, and frequently promise particular rewards for loyal performance: for example, properly following the "jaya," or "victory," festival is claimed to assure that one's intended objective would be achieved.
You may also want to read more about Hinduism here.
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