English: Day to day change in equation of time, and length of solar day. Calculated for March 1, 1999 to March 1, 2000, using

${\displaystyle \Delta t_{ey}=-7.659\sin {M}+9.863\sin \left(2M+3.5932\right)}$ minutes

${\displaystyle M=6.240\,040\,77+0.017\,201\,97D}$

(from w:Equation of time) where D is days after January 1, 2000, at 12 GMT.

The longest solar day in this period was:

December 23, 28.1 seconds over 24 hours

The shortest was:

September 16, 22.5 seconds less than 24 hours

There was a "local maximum":

June 20, 12.7 seconds over 24 hours

and a "local minimum":

March 28, 18.6 seconds less than 24 hours.

The difference between the longest and shortest solar days was therefore 50.6 seconds.