The objective time of "local noon" also varies due to the Earth's orbit not being a perfect circle, and the Earth's axis being tilted with respect to the plane

The objective time of "local noon" also varies due to the Earth's orbit not being a perfect circle, and the Earth's axis being tilted with respect to the plane of its orbit. The variance is described by the equation of time: https://en.wikipedia.org/wiki/Equation_of_time https://en.wikipedia.org/wiki/Equation_of_time