Originally published by Swisswatches Magazine, September 12, 2024 — by Catherine Bishop
In this exclusive interview for Swisswatches Magazine's "Collector's Choice" series, Dutch watch collector and entrepreneur Ruud van Rijn — known across social media as @jumphourking — shares his deep passion for jump hour mechanisms: timepieces where the hour display jumps discretely rather than moving continuously.
A Collection 25+ Years in the Making
Van Rijn began collecting watches in the 1990s, initially drawn to unconventional models including alarm watches, 24-hour dials, and world time pieces. Over the years, he narrowed his focus exclusively to jump hour watches — pieces that were visually distinctive and relatively affordable at the time. Today, his collection spans hundreds of examples across multiple centuries of horological history.
From Collector to Creator
Beyond collecting, Van Rijn is pursuing two ambitious projects: publishing "Jump Hour Designs," a comprehensive book addressing the underrepresentation of jump hour mechanisms in horological literature, and developing his own timepieces under the deRhenum brand — including the Bullhead chronograph and the Space Jump Hour, a limited edition of just 25 pieces.
The Hunt Never Stops
Van Rijn scouts approximately 25–30 online auction platforms weekly, including eBay, Invaluable, and Lot-tissimo. He also regularly attends the Rikketik watch fair in his native Utrecht, Netherlands.
The Ultimate Jump Hour
When asked about the finest contemporary jump hour watch on the market, Van Rijn points to F.P. Journe's Vagabondage III, followed by the Porsche Design Eterna Porsche Indicator. His dream acquisitions include an Eberhard jump hour chronograph, a seventeenth-century Campani clock, and a De Bethune jump hour model.
