Miyota Caliber JR20

The Miyota caliber JR20 is a multi-functional quartz movement with a day-date calendar complication. Based on official documentation, this movement has been available since at least February 2008.

As of this caliber listing, the JR20 has been discontinued.

Notable Features:

The JR20 has a pointer date subdial at 3:00, along with a fanning retrograde day of the week centered at 6:00. Additionally, the 9:00 subdial displays a 24 hour hand, useful for military time or as a day/night indicator.

Similar Calibers:

The JR family of multi-function movements also includes JR00 and JR10. The differences are the layout of the subdials and retrograde DOTW:

• JR00 – Date at 12:00; retrograde day at 4:30; 24 hour indicator at 9:00
• JR10 – Date at 12:00; retrograde day at 6:00; 24 hour indicator at 9:00
• JR20 – Date at 3:00; retrograde day at 6:00; 24 hour indicator at 9:00

Notes about setting the calendar:

Do not attempt to set the date while the hands are between the hours of 9:00 PM and 1:00 AM.

Do not attempt to set the day while the hands are between 11:00 PM and 3:00 AM.

Do not stop advancing the day of the week hand when the hand is pointing to the middle of the markers – always complete the advancement so that the hand is pointing to the marker. If by chance the hand lands between the markers, simply slowly turn the crown clockwise until it is pointing toward the correct marker.

Replacement Prices:

Despite the calibre JR20 being discontinued, at the time of this post it is readily available from various watch parts suppliers. Replacement prices were found in the range of $14.79 USD to $26.95 USD.

Additional Resources:

• Official JR20 instructions manual (pdf)
• Cal. JR20 technical drawings (pdf)
• More Miyota mentions