The Seiko 8V36A is a refined quartz analog movement featuring a sophisticated perpetual calendar function. Produced during the early 2000s, this caliber integrates high-precision quartz technology with a calendar system that automatically adjusts for month lengths and leap years until 2100. The 8V36A is widely used in Seiko’s executive and dress watches, offering users a blend of accuracy, convenience, and classic styling.

Technical Specifications

• Caliber Number: 8V36A

• Movement Type: Quartz (Analog)

• Display Features:

  • Hours, minutes, seconds hands

  • Date window (typically at 3 o’clock)

  • Optional day-of-week indicator

• Calendar Function: Perpetual calendar, programmed through February 28, 2100

• Accuracy: ±20 seconds per month (thermo-compensated quartz oscillator)

• Battery Type: SR927W (1.55V silver oxide)

• Battery Life: Approximately 7 to 10 years

• Jewels: None (electronic movement)

• Crown Positions:

  • Position 0: Normal operation

  • Position 1: Date/day adjustment

  • Position 2: Time adjustment

Key Features

Perpetual Calendar

• Automatically adjusts for months with 30 or 31 days.

• Correctly accounts for leap years including February 29.

• Eliminates manual date correction needs for nearly 100 years.

Timekeeping Accuracy

• Equipped with a thermo-compensated quartz oscillator for stable and precise timekeeping.

• Accuracy maintained within ±20 seconds per month.

Date and Day Display

• Date displayed in a window, most commonly at 3 o’clock.

• Some versions include a day-of-week display for enhanced functionality.

• Instant date change at midnight ensures smooth transitions.

Battery Efficiency

• Efficient power consumption affords long battery life.

• Utilizes SR927W silver oxide battery, lasting approximately 7 to 10 years.

Operating Instructions

Time Setting

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

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

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

Date and Day Adjustment

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

2. Rotate clockwise to adjust the date.

3. Rotate counterclockwise to adjust the day (if applicable).

4. Avoid setting the date manually between 9 PM and 2 AM to prevent damage.

Battery Replacement and Maintenance

• Use an SR927W silver oxide battery for replacement.

• Battery life ranges from 7 to 10 years depending on usage.

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

• No AC reset is generally needed after battery change.

• Regular maintenance includes gasket inspection and pressure testing.

Maintenance Recommendations

• No lubrication is necessary as the movement is fully electronic.

• Avoid exposure to strong magnets and shocks to preserve accuracy.

• Clean the watch regularly, particularly after exposure to moisture or dirt.

• Water resistance testing is advised periodically for watches used in aquatic environments.

Watches Using the 8V36A

The 8V36A is fitted in Seiko’s:

• Executive and dress quartz watches with perpetual calendar functions.

• Cases made from stainless steel, titanium, or precious metals.

• Watches combining classical design with advanced quartz technology.

Summary Table

Conclusion

The Seiko 8V36A quartz movement delivers a harmonious balance of precision, durability, and ease of use. Its perpetual calendar mechanism provides decades of worry-free date accuracy, while the long-lasting battery and robust quartz timing ensure consistent performance. With its elegant analog display and modern technology, the 8V36A is a reliable choice for those seeking a sophisticated timepiece that blends classic styling with cutting-edge quartz innovation.