No founder, proclamation, or establishing document for National Steven Day has been identified. A Federal Register search for the exact phrase returns no documents. The earliest archived listing of a December 20 Steven day is an Internet Archive capture from 2022, which dates the listing rather than the day.
The v spelling is older than it looks
Steven is not a modern American tidy up of Stephen. Behind the Name files it as a medieval English variant, and separately as a Dutch variant of Stefan.


