Festival story · 3 tellings · East India, North India, South India
Vishvakarma Puja and the builders' communities
How and when Vishvakarma is worshipped: the solar date in Bengal and the east, the day after Diwali elsewhere, and the craft communities who trace themselves to his five sons.
East India · Bengal, Odisha, Assam, Jharkhand, NepalAll traditions🪔 Vishvakarma Puja
In Bengal, Odisha, Assam, Jharkhand, Tripura and Nepal the puja is fixed by the sun's entry into Virgo, the last day of the Bengali month of Bhadra, so it falls on 17 September in most years. It is kept mainly on shop floors: workers pray for safe conditions and smooth machines, tools are worshipped and rested. In Kolkata the day is the great kite-flying day. The eastern image is a young man with a moustache on an elephant.
Vishvakarma is also worshipped the day after Diwali, alongside Govardhan Puja. The western and north-western image is an old, white-bearded, four-armed man with a goose, his sons around him.
What is different here:
Lunar date in the Diwali season; a different image of the god.
The Vishvakarma communities: five sons, five crafts
South IndiaFolkVishvakarma / Kammalar craft communities
Carpenters, blacksmiths, metal casters, stonemasons and goldsmiths, known together as Vishvakarmas (Kammalar in Tamil), trace their five groups to his sons Manu, Maya, Tvashta, Shilpi and Vishvajna, and keep Rishi Panchami as the day the five met to honour their father. Their Vishwakarma Puranam tells of a lodestone fort that no weapon could breach until it was burnt through treachery, scattering the craftsmen.
What is different here:
A community origin tradition with its own day and its own legend, not a temple or factory festival.
Sources: Wikipedia: Vishvakarma; Vishvakarma Puja; Vishwakarma (caste); Hindu Blog: Why is Vishwakarma Puja celebrated on September 17?; The Space Ink: Kite Flying and Vishwakarma