Glossary
The rotating disc inside the movement, printed with the numbers 1 through 31, that advances daily to display the date in the date window.
The date wheel's printed font and color should match what the manufacturer used for that reference and era; replacement date wheels sourced aftermarket often show a visibly different typeface. It's one of the smaller details authenticators compare against verified genuine examples.
Browse the full glossary, or look up a serial number in the registry.