Purattasi month is one of the holiest months in the Tamil calendar. It is the sixth month of the calendar. The month falls during the period, mid-September to mid-October and is dedicated to the worship of Lord Vishnu. All Saturdays in this month are believed to be auspicious to worship Lord Vishnu in the form of Lord Venkateshwara and get his wealth blessings. People generally observe a fast on all five Saturdays of Purattasi month. They avoid non-vegetarian food and also smoking and drinking.

In Purattasi month, the Sun will be in the sign Virgo, ruled by Mercury whose overlord is Vishnu, the God of wealth. Legend says that Lord Vishnu came to earth, landing in Tirupati Hills, as a human form, Venkateshwara, during this month. It is also believed that Shani (Saturn) loses his powers during this period. Worshipping Lord Vishnu on Saturdays can earn you his abundant blessings and reduce the adverse effects of Saturn.

There is also a scientific reason to avoid eating meat during this month. The rays of the Sun become weak, and the rains begin. The earth would have become heated up during the previous months. When it rains, the earth gets soaked and gives out heat, which is more harmful than the summer heat. During this time, the digestive power of people is also weakened, and this will have a negative effect on the digestive system. This is also the breeding period for many creatures. These are the reasons why people avoid consuming meat.

During the rainy season, there are chances of getting water-borne infections and diseases like hepatitis and cholera. There is reduced immunity as the protective and disinfecting effect of the Sun’s bright rays are also diminished. It is also the breeding season for many creatures.

Devotees make it a point to visit Perumal (Vishnu) temples on Purattasi Saturdays. In astrology, the 6th Rasi (zodiac sign) is Kanni (Virgo) and the Tamil month that represents this is Purattasi. The zodiac sign is ruled by Mercury/Budhan, whose overlord is Lord Vishnu and also a deity of vegetarianism. So, people visit Perumal (Vishnu) temples in Purattasi.