A California dial is a watch dial with a half-Roman, half-Arabic layout for its numerals. The Roman numerals usually run from about 10 o’clock to 2 o’clock. Rolex filed a patent for the design in 1941, and it appeared on early Rolex and Panerai watches. It still appears on modern watches.
Where it comes from
Rolex filed a patent for the dial design in 1941. It was granted on 15 July 1942 as Brevet #221643. At first the layout had plainer names. It was known as the ‘high visibility’ dial or the ‘error proof’ dial, and the names describe its purpose: numerals that are quick to read and hard to misread. The style appeared on early watches by both Rolex and Panerai. Rolex never officially called the design a ‘California’ dial. That name came much later, long after the patent was granted.
Why is it called a California dial?
The ‘California’ nickname only appeared in the 1980s. One account links it to a firm in California. In the 1980s Japan was going through a boom, and Rolex could not keep up with demand. The California firm is said to have refinished Rolex watches with this dial to fill the gap, and the layout took its name from that firm. A dial refinisher named Kirk Rich is credited with making many dials in this half-Arabic, half-Roman style.
Where can you see one today?
The layout is not only found on old watches. The Nomos Glashütte Club Campus is a modern watch that uses it. The style has also moved onto screens: the Apple Watch offers a watch face in this layout. To spot a California dial, look at the numerals. Roman numerals sit across the top of the dial. Arabic numerals make up the other half of the scheme.
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