Day 'N Date ST-5501
1972–1973 · Stainless
About the Day 'N Date ST-5501
Made only in 1972, the Day 'N Date ST-5501 is one of the more visually striking entries in Hamilton's Day 'N Date family, thanks to its red dial paired with a stainless steel case. It runs on the caliber 801, Hamilton's quick-change automatic movement that advances both the day and date displays. The ST-5501 is part of a broader Day 'N Date lineup that Hamilton offered through the early 1970s, with this particular reference distinguishing itself through its bold dial color and hidden lug construction.
Red dials age differently than white or silver ones, and finding an ST-5501 with a dial that hasn't faded, cracked, or taken on patchy discoloration is the real challenge. The applied indices are worth close inspection too, since any separation or misalignment tends to show up prominently against a red background. This one appeared in a single catalog year, so examples don't surface often, and clean ones are rarer still.
From the Catalog
Hamilton listed the ST-5501 simply as a stainless steel Quick-Change II with a red dial, priced at $89.95 in 1972. The Q/C II designation was Hamilton's shorthand for the independent quick-set day and date function, a practical selling point at a time when competitors were still offering single-date movements at similar price points.
Hamilton Catalog Images
1972
1973
What to Look For
| Dial | Red dials are prone to fading and uneven aging. Look across the surface in good light for color shifts, patches, or crazing. Check that the applied indices sit flush and show no signs of separation or coming loose at the edges. |
| Crystal | Confirm the crystal is clear and free of deep scratches or crazing. A hazy crystal can obscure dial condition, so ask for photos or inspect in person before committing. |
| Movement | Ask about service history. Dried oil is a genuine concern in any automatic that has been sitting, and in the caliber 801, enough friction buildup can stop the movement cold. Confirm it runs and winds smoothly before purchase. |
| Case | The hidden lug design can trap debris and grime in the recesses around the lugs. Check that the case back threads cleanly and hasn't been forced or damaged, since stainless case backs on watches of this era can be tricky to open without the right tools. |
| Crown | Cycle through all crown positions and confirm the day and date both advance cleanly. A sluggish or incomplete change on either complication usually points to a movement that needs service. |
The Movement
The caliber 801 is Hamilton's quick-change automatic, designed to advance the day and date displays independently through dedicated quick-set functions. It carries a solid jewel count and a rotor winding system suited to everyday wear. The day and date mechanism uses a series of small levers and wheels that respond well to fresh lubrication but can become sluggish or erratic when service has been deferred too long.