Varalakshmi Nombu, or Vara Mahalakshmi Vrata, is performed on a Friday in August or July. The Rahu Kalam, or the inauspicious period, on Fridays is from 10:30 to 12:00 noon. So the Varalakshmi Puja can be observed in the morning before 1030 hrs or in the afternoon. Avoid performing the puja during the Rahu Kalam period.
Usually the apt time for the Pooja is afternoon or evening. Elders say the puja should be performed when the cows return home after grazing. The fasting that begins on Friday morning (sunrise) ends when the puja is completed.
In 2013, Varalakshmi Puja is on August 16.