CA-4000
1968–1969 · 10k RGP
About the CA-4000
Made from 1968 through 1969, the CA-4000 is a calendar model from Hamilton's automatic lineup, powered by the caliber 980 and housed in a 10k Rolled Gold Plate round case. The caliber 980 is a 17-jewel automatic, and the CA-4000 pairs it with a silver dial showing baton hour markers, a day window at 12 o'clock, and a date window at 3 o'clock. The CA-4000 belongs to Hamilton's broader family of automatic calendar watches from this period, a category Hamilton leaned into heavily during the late 1960s as consumer demand for day-date complications grew.
Rolled Gold Plate cases from this era can vary a lot in how they've held up. Wear through on the lugs and caseback edges is the most common thing to find, so condition of the plating matters here more than on a solid gold case. The dual calendar display, day at 12 and date at 3, is a practical and visually well-organized dial layout that holds up nicely on originals that have been stored rather than worn daily.
From the Catalog
Hamilton's 1970 catalog listed the CA-4000 at $120.00, describing it simply as a rolled gold plate automatic with 17 jewels and a bracelet. That price point put it squarely in Hamilton's mid-tier automatic calendar offerings for that year.
Hamilton Catalog Images
1970
What to Look For
| Dial | Look at the silver dial closely for discoloration, spotting, or moisture damage around the day and date windows. Those apertures are common entry points for humidity over the decades. The baton markers should be intact and evenly seated. |
| Crystal | Check for deep scratches or crazing in the crystal. A hazy or badly scratched crystal will make reading the day and date windows difficult and affects the overall appearance significantly. |
| Movement | The caliber 980 is an automatic and should wind from normal wrist motion, but dried lubricants are common on any movement this age. Dried oil generates enough friction to stop the movement entirely, so confirm it runs smoothly and that the calendar functions are advancing correctly at midnight. |
| Case | Rolled gold plate wears through over time, particularly on high-contact areas like the lugs and caseback edges. Inspect those spots carefully. Light wear is expected, but worn-through areas that expose the base metal are hard to reverse cleanly. |
| Crown | The crown should pull to distinct positions for time setting and calendar adjustment. A loose or sticky crown can indicate stem wear or a damaged setting mechanism, which adds to service complexity. |
The Movement
The caliber 980 is a 17-jewel automatic movement, meaning it winds itself from the natural motion of the wrist via a rotor. It handles both the timekeeping and the dual calendar complication, advancing the day and date displays automatically. At this point in Hamilton's production history, the 980 reflects the company's Swiss-influenced movement engineering, built for reliable daily wear.