Now that we are in the month of March, for most of us in the northern hemisphere the worst of the winter is over, and it is only a couple of weeks until 21 March, the first day of spring. 21 March is an important date for other reasons, too. For one thing, it is used as the basis for the… Continue reading The first day of spring
Tag: equinox
How the length of a day changes over the year
The length of a solar day varies throughout the year, ranging from about 23 hours 59 minutes 38 seconds in mid-September to 24 hours 30 seconds around Christmas. This variation is caused by the Earth's elliptical orbit and axial tilt, affecting the Sun's apparent motion and leading to differences in natural time measured by sundials versus clock time.
Explaining Science 