GP Tip of the Week

The Vintage 1945 Equation of Time is a masterpiece of watchmaking technique and craftsmanship. The mechanism, reflecting the skill of a master watchmaker who seeks to reproduce celestial movements by combining a perpetual calendar with the indication of the Equation of Time, Moon Phases and the number of days in the month. The Equation of Time is a physical effect which measures the difference between Mean Solar Time (Civil Time) and the Real Solar Time; the actual length of a day is not 24-hours: it varies between -16 and +16 seconds daily which makes a maximum annual difference of +14 and -16 minutes. The 24-hour day measured by most watches is the Civil Time, which represents a compromise of the variation.