Perhaps because of the beats per hour.
By: MadSpaniard : June 8th, 2022-02:06
Hello, and interesting question. I think the Seiko Shippo enamel models like you posted have the 6R15 movement, which I believe beats at 21,600bph. That means 360 beats per minute and therefore 6 beats per second. Maybe the markers are 1/6th of a second t...