Miyota Caliber 9120

Manufacturer	Miyota
Caliber Number	9120
Base Caliber	Miyota 9100
Movement Type	Automatic, self-winding mechanical
Lignes	13.5”’
Diameter	30.2mm
Height	5.52mm
Jewel Count	26
Beat Rate	28,800 vph, 4 Hz
Lift Angle	51 degrees
Power Reserve	~40 hours
Rotor Style	Ball-bearing
Rotor Winding Direction	Unidirectional (clockwise)
Hand-Windable?	Yes
Anti-Shock Device	Parashock
Hand Count	6
Hand Sizes	1.52mm / 1mm / .17mm / .25mm
Functions	Central hours; central minutes; central sweeping seconds; 24 hour hand at 6:00; date window at 4:30; day of the week subdial at 9:00; month subdial at 3:00
Hacking Seconds?	Yes
Country of Manufacture	Japan
Known Models	(Add your watch to the comments below…)

Miyota caliber 9120 uses the framework of Miyota’s 9 series of what they categorize as “premium automatic” watch movements. The cal. 9120 is made in Japan and has 26 jewels and a frequency of 4 Hz or 28,800 beats per hour.

Functionality:

The notable feature of watches with the calibre 9120 is that is has 3 subdials that look like a 3-6-9 style chronograph watch. However, the 9120 is not a chronograph movement. The subdials are for the day of the week (9:00), month (3:00), and a 24 hour indicator (6:00). The 24 hour indicator functions like a pointer style day/night indicator – it does not indicate the time in a second time-zone.

Accuracy Rating:

According to Miyota, the calibre 9120 has an average accuracy of between -10 and +30 seconds per day. This is in normal operating conditions.

Replacement Prices:

At the time of this caliber listing, replacement prices for the 9120 were found online in the range of $102 USD – $129.99 USD.

Additional Resources:

• Official 9120 tech drawings (pdf)
• Official 91XX instructions manual (pdf)
• More Miyota watch movements