Subdial
A watch component, material or construction term describing Subdial.
Also known as: subsidiary dial, sub-dial, register
Definition
A subdial is a smaller secondary display set within the main watch dial. It can show information such as running seconds, chronograph elapsed minutes or hours, a second time zone, calendar information or power reserve. Some subdials use hands and graduated scales; others combine several indications. Their purpose depends on the movement beneath the dial, so the presence of three subdials does not by itself prove a watch is a chronograph.
Why it matters
Subdial layout can make complex information readable without adding more central hands. It also strongly affects dial balance, and collectors often use subdial position to identify movements or model variants.