Equation Of Time: What Is It And What's The Attraction?

In its simplest form, the equation of time is defined as the difference between the time displayed by the position of the sun and the time displayed by any modern clock For centuries, watch- and clockmakers have utilized mechanisms indicating the equation of time to display the difference between a true solar day and a mean solar day A true solar day is the length of time it takes for two consecutive passages of the sun to pass across a meridian at any given point; in other words, the length of time between two true noons.

During the course of a year, there are four times when mean solar time and true solar time correspond, meaning both comprise nearly exactly 24 hours Williamson's clock displayed true solar time on the dial by using a cam that adjusted the length of the pendulum throughout the year, depending on the difference between solar and mean time Due to the increase in accuracy of timekeeping, major cities around the world slowly began to adopt mean time as opposed to solar time as the standard in timekeeping: Geneva around 1780; England in 1792; and Berlin in 1810.

It's worth noting that the equation of time changes depending on the latitude of your location, meaning watches displaying the equation of time need custom cams made for different areas of the world. . Source