Day 'N Date ST-6503
1972–1973 · 14k Gold EP
About the Day 'N Date ST-6503
Made from 1972 through 1973, the Day 'N Date ST-6503 is the 14k Gold Electroplate version of Hamilton's Day 'N Date lineup, running the caliber 645 and presenting a black and gilt dial in a round case with hidden lugs. The Day 'N Date family gave buyers a quick-set day and date complication at an accessible price point, and the ST-6503 was the dressed-up option in that range, stepping up from the stainless steel ST-6501 with its Gold Electroplate finish. That two-year production window means examples are not especially common in the wild.
The black and gilt dial is the thing to focus on when evaluating one of these. Gilt dials from this era can show silvering or separation at the edges if moisture ever got in, and the day and date windows should frame their respective discs cleanly without any fogging on the inner crystal. The Gold Electroplate case finish is often worn at the lugs and high points, which is normal after fifty-plus years, but deeper wear that cuts through to base metal on the case flanks is worth factoring into the price.
From the Catalog
Hamilton's 1972 catalog listed the ST-6503 as a 14k gold electroplate Q/C II model with a black and gilt dial, priced at $105.00, which put it a step above the stainless steel Day 'N Date versions in the same family.
Hamilton Catalog Images
1972
1973
What to Look For
| Dial | Look closely at the black and gilt surface under good light. Hairline crazing, fading near the edges, or separation around the day and date cutouts all affect both appearance and value. The dial should sit flat and even in the case. |
| Crystal | Check for deep scratches or chips. Also look through the crystal at the day and date discs, they should be clean, legible, and properly aligned in their windows without any fogging underneath. |
| Movement | The caliber 645 should run smoothly and keep reasonable time. If the watch has been sitting unworn for years, dried oil can create enough friction to stop it cold. Ask about service history, and if there is none on record, budget for a service. |
| Case | Gold electroplate cases from this period show wear at the lugs and case edges, and some wear is expected. Look at how deep that wear goes. Worn through to bright base metal on large areas of the case flanks is more significant than typical high-point polishing loss. |
| Crown | The crown should thread or seat firmly and operate the quick-set day and date functions without slipping. A loose or damaged crown on a vintage watch is a water and dust intrusion risk, regardless of any original water resistance rating. |
The Movement
The caliber 645 is an automatic movement with a date and day complication, running a quick-change mechanism that Hamilton marketed as Q/C II. It advances both the day and date displays, and the quick-set feature lets you correct those displays independently without running the hands through a full twelve-hour cycle. Jewel count data is not confirmed for this specific caliber variant, but the 645 is a reliable workhorse from Hamilton's Swiss-era production and responds well to a proper service.