There are different forms of Upavasa Vratas (Fasting Penance), 1. Nirjala, 2. Nirahara, 3. Phalahara and for those for us who find it difficult but still want to participate in the vratas, ofcourse there is, the kind of food (vrata bhojana) one can take especially on the vrata days.
We can take up these vratas on Chaturti for Ganesha, Shashti for Kartikeya, Ekadashi for Vishnu, Triodashi (prodosha) for Shiva and Poornima and/or Amavasya for Shakti and some do it on the tithi or day of the Samadhi of their Guru.
First of all we will see the general rules for the vrata and then enter into the specifics.
Nirjala vrata – during the period of vrata the one who takes it should not EVEN drink water, though this is a tough form of vrata, there should not be any difficulty to perform it when doing vrata for one day.
Nirahara vrata – one can take water and should not take any type of food.
Phalahara vrata – for those who are not physically or psychologically fit to perform any of the said vrata, this is the option, where one eats fruits and nuts instead of cooked food. And here too, one should remember that we are not replacing the food with the fruits, because i have seen some people eating large quantities of fruits than that of the food they normally consume.
Vrata bhojana – the cooked food of some special type of cereals etc are used for this. Normally Sabhudhana (sago), Kuttu (buckwheat), Moongphali (Groundnut) are taken. For cooking this, generally groundnut oil is used or ghee (clarified butter). Though we use salt for cooking, it is not the general salt we use for this but Saindha namak (rock salt). Rice is a definite no in both south and north, but in south they take wheat during these days but in north wheat etc is not taken as vrata food.
Ganesha vrata is done on chaturti (fourth) of both shukla and Krishna paksha (waxing and waning of moon). Normally on this day the first and foremost predominant thought should be of Lord Ganesha. The vrata is broken on the next day.
Shashti vrata is done in the sixth day of both paksha for Lord Kartikeya. And there is also the special occasion of Skhanda Shashti, from the pratama (first day) to the sixth day immediately after deepawali festival. During this whole period the vrata is undertaken.
Ekadashi vrata is performed on the eleventh day of both pakshas for Lord Vishnu. On this day the vrata is taken and is completed on the next day morning. There is one ekadeshi which is specifically Nirjala Ekadeshi too, once in a year.
Pradosha vrata is performed generally on the thirteenth (and sometimes it comes on the twelfth day, please refer to the calendar to be particular). The vrata starts on the morning of the day and is completed in the evening after the darshan (vision) of Pradosha Puja )a special puja is performed in the Shiva temples from 4.30 – 6.30 pm). If this is difficult, at least the darshan of Shiva image is good enough. Special Shiva vrata is performed on Shivaratri, that starts from the early morning of the first day to the next day morning.
The vrata for devi is generally performed on Amavasya or Poornima (new moon or full moon). Some people takeup this vrata on every Tuesday too. The most elaborate and lengthy of this vrata is performed on the Navratri (both devi navaratri and rama navami).
How necessary is it to perform these vratas? As the name both in Sanskrit and English suggest, from “vrtu vartane” – to exist, and Fast-ing, it is good for speeding up the process of mind purification and strengthening the will power.
Who should perform? Anyone interested in the grace of the Iswara. This is also taken by the yogis as a method of cleansing the body.
Smart Mauni speaks : “I remember the monkey which decided to do vrata, thought it will be weak after the vrata, so first plucked some bananas, after that thought it will be weak to peel so did it, then thought it will be weak to chew and later thought it will be weak to gulp it an thus completed the vrata”