Miyota Caliber 0S00

Miyota caliber 0S00 is a quartz chronograph watch movement with a day/date complication at 3:00. It is made in Japan and has 0 jewels.  This caliber is a member of Miyota’s 0S “Professional” family of quartz chronograph movements. Miyota is owned by Citizen Watch Co. Ltd. The crossover or corresponding Citizen caliber number is 0500.

0S00 Functions:

In addition to its day/date calendar complication, the 0S00 features a central chronograph stopwatch seconds hand, 60 minutes chronograph counter subdial at 12:00, 12 hours chrono subdial at 9:00, and a small running seconds at 6:00. Miyota calls this layout a Vertical 3 Eyes chronograph.

In Miyota’s own words this movement features:

• Quick Reset (by Heart Cam Reset System)
• Click Feeling Push Button Handling
• TACHYMETER Available

Day/Date Calendar Options:

The standard configuration of the day/date on the 0S00 is a square shape white background with black letters at 3:00. These movements are usually readily available for wholesale purchase with a minimum order of 500 pieces. There are two other options available for a more unique look: square shape black background with white letters and round date shape black background with white letters. These options are special orders with about a 2 month lead time and minimum order of 1,000 pieces.

0S00 VS 0S06:

There is a similar caliber 0S06. This is the high hand version of the 0S00. It is used when the dial design is thicker (like deep dish) and requires the hands to be positioned higher than the standard 0S00.

Accuracy:

Miyota claims that the accuracy of the 0S00 is within +/-20 seconds per month in normal operating temperatures.

Battery Life:

According to Miyota, the correct SR927W (395/399) battery cell should last about 5 years in the caliber 0S00. This estimate is up from 2 years seen in many Miyota quartz chronographs, such as the caliber 0S60.

Miyota’s battery life claims are based on using the chronograph function for 60 minutes or less per day. Running the chronograph means the watch is working harder and this reduces the battery life. For that reason, it is advised to only use the chronograph when you need it.

If you are not going to wear your watch for a while and want to save the battery, pulling out the stem (aka hacking the movement) will reduce the battery consumption.

Replacing the Battery:

The battery is held in place with tension. Te remove the battery, gently move the tension arm back with your tool to allow the battery to pop out. The install a new battery, make sure the cell slides under the fix tab and hold the tension arm back, push the battery down and slowly release the tension arm back into place with the top tab holding it in place. The “tension arm” as described here is circled in the image below.

Resetting the OSOO chronograph to zero:

If your chronograph hand is not resetting to 12:00 or “zero” position, then you can try the following steps:

1. Pull the crown to position 2 (time setting position).
2. Press button A to advance the chronograph hand forward until it is lined up with 12:00. If you long-press A, the hand will move forward faster.
3. Push the crown back to position 0

Note: if you push the crown back in to position 0 while the chronograph hand is still advancing forward, then it will stop the chronograph hand and recognize it as zero position. In this case, you will have to start over again.

Replacement Prices:

At the time of this caliber listing, replacement prices for the 0S00 were found online in the range of $27.95 to $29.60 USD.

Additional Resources:

• Miyota 0S00 tech drawings
• Miyota 0S00 instruction manual

Not OS00, OSOO, 0SOO