Vishnupati or Vishnupathi Punyakalam is the most auspicious period of time for Vishnu Puja. Vishnupathi Punya Kalam is observed once in three months and four times every year. In 2015, second Vishnupati Punyakalam date is May 15.
The general time to observe Vishnupathi is 1:30 am to 10:30 am (9 hours). Usually, Vishnupati is celebrated on the day when Sun transits to Aquarius, Taurus, Leo, and Scorpio (Kumbha Sankramana, Vrushabha Sankramana, Simha sankramana, and Vrischika sankramanam).
May 15, 2015, is Vrushabha Sankramana day. Vrushabha masam (Edavam month) begins in Malayalam calendar and Vaikasi masam starts in Tamil calendar.
Next Vishnupati Punyakalam 2015 dates are in August 2015 and November 2015.