Certina Caliber 25-652: A Sturdy Swiss Day-Date Automatic for Everyday Use

The Certina Caliber 25-652 stands out as one of the most refined and practical automatic movements produced by Certina in the late 1960s and early 1970s. Designed as part of the robust 25-series, this caliber added both a day and date complication, offering wearers enhanced functionality in an elegant mechanical package.

Intended for everyday watches that balanced utility and durability, the 25-652 was frequently found in Certina DS (Double Security) models and standard automatic wristwatches. Its design reflects a period in Swiss watchmaking when brands aimed to combine mechanical integrity with real-world convenience.

Technical Specifications

This caliber offered an excellent balance between performance, serviceability, and daily functionality, particularly with the day-date feature being increasingly popular during the period.

Movement Design and Mechanical Construction

The 25-652 evolved from earlier 25-series calibers, specifically adding a dual calendar complication (day and date) while maintaining the same core architecture. Its rugged build and bi-directional winding system made it efficient and reliable, even under daily wear.

Key Features:

• Bi-directional winding rotor, improving power reserve replenishment

• Day and date display with wheels driven by the hour wheel via a date-change system

• Shock-protected balance assembly using the Incabloc system

• Full bridge construction for better stability during regulation

• Central seconds hand, offering clean dial symmetry and accurate reading

The movement does not feature a quickset function, meaning the day and date must be set by advancing the time past midnight repeatedly—common in mechanical watches of this era.

Applications in Certina Watches

Watches housing the 25-652 were aimed at consumers seeking practical mechanical wristwatches that offered useful features like a dual calendar but with the ruggedness and style expected from Certina.

These watches typically include:

• 35–38 mm cases, often in stainless steel or gold-plated brass

• Day-date windows at 3 o’clock, either with dual windows or combined apertures

• Applied indices, luminous baton hands, and anti-reflective crystals

• “Certina Automatic” and/or “DS-2” markings on the dial

• Screw-down or snap-back casebacks depending on the model line

The movement was particularly well-suited to the DS (Double Security) case architecture, which added water and shock resistance for a more rugged wrist presence.

Watchmaker Perspective and Service Notes

The 25-652 remains watchmaker-friendly, with most components still available through donor movements or vintage parts suppliers. Its straightforward construction, despite the added calendar functions, makes it a reliable candidate for restoration and long-term use.

Servicing Advice:

• Lubricate calendar works lightly to ensure smooth switching (avoid over-oiling)

• Clean day and date wheels carefully to preserve printed fonts

• Inspect reversing wheels and rotor bearings for wear, especially in older pieces

• Target amplitude: 270–300° post-service with proper lubrication

• Regulate to within ±10–15 seconds/day for optimal performance

Calendar setting should always be done outside of the date-change window (avoid setting between 9 PM and 3 AM) to avoid damaging the gears.

Value to Collectors and Enthusiasts

Though not considered a high-complication movement, the 25-652 remains highly respected for its functionality and build quality. Collectors value it for:

• Classic Swiss engineering

• A dependable dual-calendar feature

• Its use in handsome, understated vintage models

• Ease of service and reliable performance

Today, watches powered by the 25-652 offer great value as vintage daily wearers, especially for enthusiasts who prefer mechanical over quartz and appreciate the charm of traditional calendar displays.

Conclusion

The Certina Caliber 25-652 is a well-balanced automatic movement that showcases Certina’s commitment to durable and practical Swiss watchmaking. With its clean layout, day-date functionality, and proven mechanical design, it continues to be appreciated by vintage watch collectors and everyday users alike. Whether you’re restoring one or wearing it as a dependable timepiece, the 25-652 delivers performance that endures across decades.