September 22 2024 – the equinox

In 2024 September 22 is the date of the September equinox and is also the first day of autumn (or the first day of spring if you're one of my readers in the Southern Hemisphere). In this post I’ll talk about the equinoxes and discus the commonly held, but not quite correct, view that they… Continue reading September 22 2024 – the equinox

Understanding Solar Day Length Variation

Revised and updated 18 December 2025 July 25,  is one of the four days a year in which the length of the solar day,  the natural day measured by the rising and setting of the Sun, is 24 hours. I have written about this in previous posts but I thought it be worth mentioning it… Continue reading Understanding Solar Day Length Variation

September 23 2023 the equinox

In 2023 September 23 is the date of the September equinox and is also the first day of autumn (or the first day of spring if you're one of my readers in the Southern Hemisphere). In this post I’ll talk about the equinoxes and discus the commonly held, but incorrect, view that they are the… Continue reading September 23 2023 the equinox

The equinox 20 March 2023

In 2023 March 20 is the date of the March equinox and is also the first day of spring (or the first day of autumn if you're one of my readers in the Southern Hemisphere). In this post I’ll talk about the equinoxes and discuss the commonly held, but not quite correct, view, that they… Continue reading The equinox 20 March 2023

The equinox 20 March 2022

In 2022 March 20 is the date of the March equinox and is also the first day of spring (or the first day of autumn if you're one of my readers in the Southern Hemisphere). In this post I’ll talk about the equinoxes and discuss the commonly held, but incorrect, view, that they are the… Continue reading The equinox 20 March 2022