Miyota Caliber FS00 Watch Movement

Manufacturer	Miyota (Citizen)
Caliber Number	FS00
Type	Quartz
Lignes	10.5”’
Diameter	23.7mm
Height	4.13mm thick
Minimum Case Size	35.1mm
Minimum Case Thickness	9.43mm
Jewels	0
Battery Cell	SR626W
Battery Life	~2 years
Frequency	32,768 kHz
Quartz Type	Tuning fork type quartz crystal
Accuracy	+/- 20 seconds per month
Hacking?	Yes
Stem	065-549, tap 10
Hand Sizes	1.2mm / 0.70mm / 0.17mm / 0.26mm
Hand Count	6
Crown Location	3:00 with pushers at 2:00 and 4:00
Functions	Central hours, central minutes, central chronograph seconds, 60 minutes chronograph totalizer at 10:00, 24 hour subdial at 2:00, small running seconds at 6:00, date at 4:00 or 6:00.
Country of Manufacture	Japan
Known Models	(Add your watch in the comments below…)

Miyota caliber FS00 (sometimes written FSOO) is a quartz chronograph watch movement with a date at 4:00. It is made in Japan and has 0 jewels. This caliber is a member of Miyota’s FS family of quartz chronograph movements. It is considered a “small” chronograph compared to the OS family of movements. Miyota is owned by Citizen Watch Co. Ltd. The crossover or corresponding Citizen caliber number is F500.

Some of the topics covered in this caliber listing:

FSXX Functions

Date at 4:00 or 6:00 (this could vary depending on the watch design)
24 hour time at 2:00. This is not set independently. In other words, it is simply the same time as the central time display, but showing what time it is on a 24 hour scale aka military time.
Small running seconds at 6:00.
60 minutes chronograph subdial at 10:00. This means that the chronograph can time 60 seconds with the central chronograph stopwatch hand, and up to 60 minutes with this subdial.

In Miyota’s own words this movement features:

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

Similar Calibers

Miyota’s official documentation on the caliber FS00 is combined with the FS10 and FS20. These movements are all part of the Miyota FS family of 10.5”’ quartz chronograph movements, with the main difference being the placement of the chronograph subdials. The differences are listed below:

FS00 – 24 hrs at 2:00, small seconds at 6:00, 60 minute chrono counter 10:00, date at 4:00
FS10 – 24 hrs at 12:00, small seconds at 6:00, 60 mins chrono counter at 9:00, date at 3:00
FS20 – 24 hrs at 3:00, small secs at 6:00, 60 mins at 9:00, date at 4:30

Another difference between these calibers may be the overall height. The FS00 is said to be 4.13mm, but the FS10 and FS20 may be 5.10mm tall.

Date Calendar Options

The standard color and location of the date on the FS00 is a datewheel with black numbers on a white background at 4:00 (FS00-10A). This configuration is usually readily available for wholesale purchase from Miyota with a minimum order of 500 pieces – or individually from resellers. A date at 6:00 is also possible for standard order (FS00-10Y).

There is another option available for a unique look. It is possible to have a datewheel with white numbers on a black background (FS00-10Z). This option is a special orders with about a 2 month lead time and minimum order of 1,000 pieces.

Accuracy

Miyota claims that the accuracy of the FS00 is within +/-20 seconds per month in normal operating temperatures.

Battery Life

According to Miyota, the correct SR626SW (376/377) battery cell should last about 2 years in the caliber FS00.

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 FSOO chronograph to zero

If your chronograph hand is not resetting to 12:00 or “zero” position (such as after a battery change), then you can try the following steps:

Pull the crown to position 2 (time setting position).
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.
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.