Day 'N Date ST-5500
1972–1973 · Stainless
About the Day 'N Date ST-5500
Made from 1972 through 1973, the Day 'N Date ST-5500 is a stainless steel round-cased automatic carrying Hamilton's caliber 801, a movement built around the full day and date complication that gave this family its name. The ST-5500 came in two configurations at launch: strap or bracelet, with pricing reflecting the difference. Part of Hamilton's Day 'N Date family, this model represents the stainless steel entry point into that line during its early 1970s run.
The blue dial is the defining feature here, and condition matters more than usual on blue dials from this era because fading and spotting tend to show clearly against that background. Applied indices give the dial some depth and help it hold up visually even when the surface shows age. Finding one with a clean, unrestored blue dial and solid case integrity makes it worth a careful look.
From the Catalog
Hamilton's 1972 catalog listed the ST-5500 straightforwardly as a stainless steel model with the Q/C II blue dial, available on strap for $79.95 or on bracelet for $89.95, positioning it as an accessible entry into the Day 'N Date line without a lot of extra framing.
Hamilton Catalog Images
1972
1973
What to Look For
| Dial | Examine the blue dial closely for fading, spotting, or moisture damage. Blue dials from this period are vulnerable to uneven discoloration, and any restoration or refinishing will significantly affect value. The applied indices should be flush and evenly seated with no separation or detachment at the edges. |
| Crystal | Check for deep scratches or crazing in the crystal. A replacement mineral or acrylic crystal is easy and inexpensive to sort out, but confirm what's there so you know what you're working with. |
| Movement | Ask about service history. In an automatic that has been sitting unworn, dried oil creates enough friction to stop the movement entirely, and the caliber 801 is no exception. Confirm the watch runs, winds smoothly through the rotor, and sets cleanly through the crown. |
| Case | The hidden lug design on the ST-5500 means lug wear and dings can be subtle but are worth inspecting carefully on the underside. Check the caseback area for tool marks from prior openings, which can indicate service history and also signal how carefully the watch has been handled. |
| Crown | Work the crown through all its positions and confirm the day and date both advance and snap over cleanly. Sluggish or partial changes usually mean the movement needs attention. Also note that this watch is not suitable for water exposure regardless of any original rating. |
The Movement
The caliber 801 is a Swiss-made automatic with a full day and date complication, designed around Hamilton's quick-change mechanism for advancing both displays independently. It's a fairly robust movement for everyday wear, though like any automatic from this era it benefits from a proper service if it hasn't had one recently. Jewel count data isn't confirmed for this specific caliber variant, so that detail is best verified on inspection.