The Miyota caliber 0S20 is a quartz chronograph watch movement. You might also see other listings incorrectly refer to this movement at OS2O, but is should be zero-S-2-zero not O.
Miyota claims the accuracy of this movement to be +/-20 seconds/month.
Recalibrating the chronograph hand to zero:
It is common for a quartz chronograph hand to be misaligned after a battery change. If your central chronograph second hand (or chronograph minute hand) is not resetting to 12:00 or “zero” position, you can try the following steps:
Pull the crown to position 2
Press button A (top button) 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 button B (bottom button) to reset the 60 minute chronograph hand (subdial located at 9:00).
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.
The average replacement price at the time of this post was from $26.95 – $36.95. Try here.