The Chaturmasya Vrata period usually commence during the month of Ashadha (June-July) and ends in the month of Karthika (October-November). During this period, it is believed that Lord Vishnu used to perform meditative sleep (Yoga Nidra). Hence by observing fasting on these months, we would get the immense blessings of Lord Vishnu.
Chaturmasya Vrata can be observed by saints as well as by family men. But mostly this Vrata would be observed only by saints. The main purpose of observing this fasting is to control our senses, and to stop doing bad karmas.
During these months, certain food items must be avoided. Non vegetarian food items must be strictly prohibited during this period. In general, during the entire period of Chaturmasya, one should practice eating only simple vegetarian food.During the festivals likeSri Rama Navami, Sri Krishna Jayanti, and Vinayaka Chaturthi, the Prasad items must be first offered to the Lord, by considering that god would taste some quantity of Prasad, and then only we have to consume the remaining Prasad items.
Chaturmasya vrata must be observed for showing our sincere bhakti on Lord Krishna. Similar to the great Vittal devotee ChokaMela, we have to surrender our entire soul and body on to him, and our each and every cell must praise, and sing glorious songs on him.
After the completion of the Vrata, we can first drink some fruit juices and butter milk, and then after some time, we can have our normal diet.
As per the Holy Vedas, it is told that whoever observes the Chaturmasya Vrata in a proper manner would get all kinds of prosperity in this earth during his life time, and after his death he would reach the abode of Lord Indra, the Swarga Loka, and can enjoy by happily living in the divine world for several thousands of years.
Great saints like AdiShankara, Madhwacharya, Ramanuja and Guru Raghavendra had observed this holy Chaturmasya Vrata, and due to that, they have become enlightened.
Saints are supposed to travel throughout the world, to preach the greatness and the sweetness of our Hindu religion, but during the rainy months which mostly occurs from July to October, it is not possible for them to travel to distant places, and they would remain at one place only.Hence during this period, they would observe the Chaturmasya Vrata.
Before observing the Chaturmasya Vrata, saints like Kanchi Acharya, Madhwa pontiffs and pontiffs of Sarada Shakti Peetam, would perform Veda Vyasa Puja and also perform puja to Guru Dakshinamurti, Lord Rama and Lord Krishna.