The Big Date Complication, Explained: Why Two Small Discs Are Harder Than One
A big date, or outsize date, shows the date in two large adjacent numerals using two independent discs instead of one small window. A working dealer's plain-English guide to how the two-disc mechanism works, why A. Lange and Sohne's Grossdatum set the modern standard, and what to check before buying one pre-owned.