युधिष्ठिर के पूछने पर श्रीकृष्ण इस व्रत की महिमा बताते कहते हैं कि इस एक ही व्रत के कर लेने से सात जन्मों के पाप नष्ट हो जाते हैं. Lord Shiva said to be the destroyer in the Trinity. इसके बाद प्रातः 9 बजे से 10 बजे तक दूसरे समय का पूजन तथा दिन में तीसरे समय का दिवा वा यदि रात्रौ वा नास्ति चेद् रोहिणी-कला।रात्रियुक्तां प्रकुर्वीत विशेषेणेन्दु- संयुताम्’।। अर्थात्, दिन या रात कभी भी रोहिणी नहीं हो, तो केवल मध्यरात्रि में चंद्रोदय-व्यापिनी अष्टमी को ही व्रत करें. Chhath Puja is an ancient Hindu festival dedicated to the Sun (Lord Surya) and its first & last ray of light, Usha and Pratyusha to thank them for bestowing light, energy, and life on earth as also to promote the well-being, development, and prosperity of human beings and to request them to grant their wishes.
There is a method of eating and bath on its first day. It is believed that the sages and rishis from that era practiced this method to restrain from external means of food and instead gain energy from the sun directly.Apart from religious significance, there are many other scientific facts attached to these rituals.