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The Seiko A828A is a feature-rich quartz digital movement designed in the late 1980s to support Seiko’s world time watches. This module is well known for its practical layout, dual time zone capability, and city code-based world time functionality—all presented through a classic digital LCD interface. Compact, accurate, and traveler-friendly, the A828A became a go-to movement for frequent flyers and those needing to track multiple time zones.

Technical Specifications

• Caliber Number: A828A

• Movement Type: Quartz (Digital LCD)

• Display Type: 7-segment Liquid Crystal Display (with city code window)

• Primary Functions:

  • 12-hour or 24-hour timekeeping (user selectable)

  • Calendar (Day and Date)

  • Daily Alarm

  • World Time Function (29 cities/time zones)

  • Local Time and Home Time toggle

• Backlight: Not integrated into the module (some models feature external lamp or electroluminescent lighting)

• Battery Type: CR2016 (3V lithium coin cell)

• Battery Life: Approximately 2–3 years

• Accuracy: ±15 seconds/month

• Module Dimensions:

  • Width: ~26 mm

  • Height: ~22 mm

  • Thickness: ~5 mm

Display Layout

The Seiko A828A offers a clean and efficient LCD readout, often housed in rectangular cases with labeled bezels or rotating city-code rings.

Display Elements:

• Top Line:

  • Day of the week (MO, TU, etc.)

  • Mode indicators: AL (alarm), WT (world time), PM/24H

  • City code (three-letter abbreviation, e.g., NYC, TYO, LON)

• Main Display Field:

  • HH:MM:SS (in both local and world time modes)

  • Calendar shown as MM-DD or DD-MM depending on regional settings

This display is ideal for quick reading of time across two zones.

Operating Modes

The A828A supports five primary modes, accessed via a mode button:

1. Timekeeping Mode (Local Time)

• Displays hours, minutes, and seconds

• AM/PM indicator or 24H mode

• Syncs with calendar

2. Calendar Mode

• Displays current day and date

• Manual correction required for shorter months

• Leap year logic not included

3. Alarm Mode

• One daily alarm

• Settable by hour and minute

• Alarm ON/OFF toggle

• “AL” icon displayed when active

4. World Time Mode (T2)

• 29 preset cities selectable using buttons

• Displays second time zone (T2) while retaining T1 in memory

• Updates time based on internal offset for each city

• Great for travelers or professionals working across time zones

5. Time Swap / T1↔T2

• Allows quick swapping between local time and world time

• Useful when traveling — makes your destination the new “local” time in one press

Button Layout

Typical watches powered by the A828A include four buttons:

• MODE – Cycles through functions (Time → Alarm → Calendar → World Time)

• SET – Activates setting mode

• ADVANCE – Adjusts values / Changes city code in World Time

• SWAP – Switches between T1 and T2 or toggles alarm ON/OFF

The button layout was intentionally designed for quick access and travel-ready functionality.

Setting Instructions

Setting the Time:

1. Press MODE to enter Time mode

2. Hold SET until digits flash

3. Use ADVANCE to set hour, minute, and seconds

4. Press SET to move through fields

5. Confirm with MODE

Setting World Time:

1. Press MODE to enter World Time mode

2. Use ADVANCE to cycle through city codes

3. Time updates automatically for selected city

4. Press SWAP to make it your local time

Setting the Alarm:

1. Press MODE to enter Alarm mode

2. Hold SET to enter setting mode

3. Use ADVANCE to adjust hour/minute

4. Press SWAP to toggle alarm ON/OFF

Battery Replacement & AC Reset

After changing the battery, the module requires an AC (All Clear) reset to function properly.

AC Reset Procedure:

1. Open the case back with care

2. Remove the old CR2016 battery

3. Insert a new battery (check polarity)

4. Locate the AC terminal on the circuit board

5. Short the AC terminal to the battery’s negative terminal using metal tweezers

6. Hold contact for 2 seconds

7. Display will reset to default time

After reset, re-enter the time, alarm, and preferred city.

Maintenance Tips

• No lubrication required – fully electronic

• Clean buttons and case periodically, especially after travel or high humidity use

• Keep city bezel aligned if watch uses an external rotating ring

• Avoid pressing buttons underwater unless explicitly rated as water-resistant

• Replace gaskets at battery service if the watch is labeled water-resistant

Watch Models Using A828A

This module was used in Seiko World Time digital watches, often rectangular with large screens and city abbreviations printed around the bezel or on a rotating inner dial.

Famous examples include:

• Seiko A828-6010

• A828-6029 World Timer

• Stainless steel or black resin cases

• “World Time” printed prominently on the dial or bezel

These models remain collectible due to their travel functionality and clean Seiko digital design.

Conclusion

The Seiko A828A is a dependable and versatile digital movement designed for world travelers and international professionals. With dual time zone support, easy city code selection, and practical alarm/calendar features, it was a standout in Seiko’s 1980s digital catalog. Today, A828A watches remain popular among collectors and globetrotters who appreciate vintage digital engineering with real-world usefulness.