To acknowledge that lord Vishwakarma alone is the creator of all universe and the things within, and to offer worship and thankfulness to him on the Vishwakarma day, is what Vishwakarma Puja is all about. This is what lends the festival of Vishwakarma Puja its significance. The religious texts have it that it was he who brought the tripartite universe - heavenly realms and their worlds, the mortal realm and their worlds, and the netherworldly and other celestial realms and worlds into existence. It was he who created Swarga (Heaven) in the Satya Yuga; Sone ki Lanka (Golden Lanka) in the Treta Yuga; the city of Dwarka, the capital of Lord Krishna in the Dwapara Yuga; and many other architectural marvels into existence out of thin air. It was he who formed the chariots and various weapons of Gods and gave each its unique divine attributes. And it was he who revealed the sciences of industry to us because of which we see the progress that has been made.
Lord Vishwakarma is described as the ultimate reality in the Rig Veda, whose name in Sanskrit means "All Accomplishing", and who is believed by the Hindus to be the "Principal Universal Architect" who gave form to the celestial architecture of all that is in this universe with his own hands. And as a mark of reverence, he is worshipped as the patron of all the engineers, architects, artisans, craftsmen, weavers, mechanics, smiths, welders, industrial workers, and factory workers. Falling on Padyami, the first day of Kartika Masa, Vishwakarma Puja is observed on the fourth day of Diwali, i.e. the day after Diwali. In some parts of the country including Bihar, Jharkhand, West Bengal, and Orissa, Vishwakarma Puja is observed on 17th September every year and doesn't change according to the lunar calendar.
On the day of Vishwakarma Puja, the industries and factories observe a no-work day; but, are heartily open for the entire workforce and their families to come and participate in the rituals. During the day of the puja or a day before, colorful pandals are set up inside the premises of industries and factories after which the decorated idols and images of Lord Vishwakarma are brought inside the pandals and are established ritualistically. The entire unit - management, employees, and workers, along with their families come together to perform the puja. Even the tools, particular to each person's profession, are worshipped in the name of Lord Vishwakarma but aren't put to use until the next day. Thereafter, Prasad (offerings) is distributed among everyone, post which everybody sits together for lunch. There's also a competitive tradition of flying colorful kites and engaging in mid-air battles, cutting each others' kites and shouting "Ibo Kaata".