The Seiko 8123A is a reliable and precise quartz analog movement designed primarily for standard timekeeping functions. Developed in the 1980s and 1990s, the 8123A reflects Seiko’s commitment to quality quartz technology, offering users an accurate and low-maintenance watch movement suited for everyday use.

Though simpler than some of Seiko’s more complex calibers, the 8123A provides robust performance with a straightforward design, making it a popular choice for many Seiko models during its production era.

Technical Specifications

• Caliber Number: 8123A

• Movement Type: Quartz (Analog)

• Display:

  • Hours, minutes, seconds hands

  • Date display window (usually positioned at 3 o’clock)

• Accuracy: Approximately ±20 seconds per month

• Battery Type: SR927W (1.55V silver oxide)

• Battery Life: Approximately 2 to 3 years

• Jewels: None (quartz electronic movement)

• Crown Positions:

  • Position 0: Normal operation

  • Position 1: Date adjustment

  • Position 2: Time adjustment

Key Features

Timekeeping

• Provides reliable and accurate time display with hours, minutes, and seconds.

• Quartz precision ensures low deviation from accurate time.

Date Display

• Date window positioned at 3 o’clock for quick date reference.

• Quick-set date adjustment via crown.

Battery Efficiency

• Uses an SR927W silver oxide battery lasting approximately 2 to 3 years depending on usage.

Operating Instructions

Time Setting

1. Pull the crown to the second click (Position 2).

2. Rotate the crown to adjust the hour and minute hands.

3. Push the crown back to Position 0 to resume normal operation.

Date Setting

1. Pull the crown to the first click (Position 1).

2. Rotate the crown to set the date.

3. Avoid setting the date between 9 PM and 2 AM to prevent damaging the date mechanism.

4. Push the crown back to Position 0.

Battery Replacement and Maintenance

• Replace battery with an SR927W silver oxide battery when the watch shows signs of power loss.

• Typical battery life ranges from 2 to 3 years.

• Battery replacement should be performed by a qualified watchmaker to maintain water resistance.

• No reset procedure is usually required after battery replacement.

Maintenance Recommendations

• No lubrication required for this quartz electronic movement.

• Avoid exposure to strong magnetic fields and shocks.

• Regularly clean the watch exterior and ensure seals are intact for water resistance.

• Have water resistance tested periodically if the watch is used in wet environments.

Watches Using the Seiko 8123A

The 8123A movement was widely used in Seiko’s:

• Entry-level quartz watches in the 1980s and 1990s.

• Models emphasizing affordability and durability over advanced functions.

• Watches with classic analog layouts and simple date functionality.

Summary Table

Conclusion

The Seiko 8123A quartz movement represents a dependable and straightforward timekeeping mechanism. Its uncomplicated design, combined with reliable accuracy and easy maintenance, makes it an enduring choice for everyday analog watches. While lacking advanced features like chronographs or perpetual calendars, the 8123A excels as a solid foundation for classic Seiko timepieces emphasizing durability and precision.