John Twaalfhoven was born in 1958. He has a wife and two daughters. The birthdays of his new family and the affinity for mechanical devices inspired him to invent and build this unique Calendar Time-Piece. It took over 15 years and thousands of hours of development. This effort was rewarded with a Swiss and European patent.
The Twelve hoven name is over 600 years old and reflects a cluster of twelve farms in the Netherlands.