1 Chhath puja is mainly observed in Bihar and Nepal Bihar has a number of Sun temples flanked by a surajkund or sacred pool of the Sun 2 It is a ritual bathing festival that follows a period of abstinence and ritual segregation of the worshiper parvaitin from the main household for four days The parvaitin observes ritual purity and sleeps on the floor on a single blanket 3 This is the only festival which does not involve any priest 4 The devotees offer their prayers to the setting sun and then the rising sun 5 It is the most glorious form of Sun worship 6 The main worshippers parvaitin are women 7 The parvaitin pray for the well-being of their family for prosperity and for offspring 8 The prasad offerings include sweets Thekua and fruit offered in small bamboo winnows 9 The food is strictly vegetarian and it is cooked without salt onions or garlic 10 Day 1 Nahay khay bathe and eat The parvaitin take a dip in river The house is cleaned Only one meal is eaten and contains kaddu-bhat or channa dal and arwa chawal rice 11 Day 2 Kharna the day before Chhath On Panchami the parvaitins observe a fast till evening a little after sunset Just after the worship of earth the offerings of Rasiao-kheer rice delicacy puris puffs of wheat flour and bananas are distributed From time onwards for the next 36 hours the parvaitin goes on a fast without water 12 Day 3 Chhath Sanjhiya Arghya evening offerings The day is spent preparing the Prasad offerings at home Offerings Argh are made in the evening to the setting sun In the night a colorful event of Kosi is held Here lighted earthen lamps are kept under a canopy of five sugarcane sticks The five sticks signify the human body made of five elements 13 Day 4 Parna day after Chhath Bihaniya Aragh next morning offerings On this final day the parvaitin with family go to the riverbank before sunrise and offer Aragh to the rising sun The festival ends with the breaking of the fast Science behind the pooja 1 Sun worship in Kartik month is related to absorption of vitamin D 2 Vitamin D comes from UVB rays 3 These rays are predominant at sun set and sun rise 4 Vitamin D deficiency today is running like an epidemic in the society 5 Vitamin D is sued for absorbing calcium from the food 6 All the food items used in this pooja are high in calcium 7 Kartik is also high fertility months Vitamin D deficiency is linked to infertility 8 Natural calcium is better absorbed in fasting state 9 Patients with compromised kidneys should not do this fast 10 Fast is never broken with feast This fast is usually broken with ginger and jaggery Disclaimer The views expressed in this write up are my own