On Monday, January 5, 2015 6:10:43 PM UTC-8, John H. wrote:
On Mon, 5 Jan 2015 07:48:20 -0800 (PST), Tim
wrote:

Gerald, it's all amazing isn't it?

And also amazing is that, according to some, it's all a random
occurrence from a big explosion.

Wow.

The words 'average' and 'constant' come into play at this juncture for the 'average' 24 hour day substitutes for 'constant' rotation at 15 degrees per hour or once in 24 hours. For instance, the average flow of a liquid through a pipe is the same thing as the constant flow of liquid through the same pipe however the timekeeping system uses 'average' as a starting point.

When accurate clocks started to emerge in the 17th century it was already known that with each sweep of the Sun across the observer's meridian, the total length of the day regardless of hemispheres varies from noon to noon. As each day corresponds to another rotation, a certain value was attached to each day to equalize it to a 24 hour average -

"Draw a Meridian line upon a floor and then hang two plummets, each by a small thread or wire, directly over the said Meridian, at the distance of some 2 feet or more one from the other, as the smallness of the thread will admit. When the middle of the Sun (the Eye being placed so, as to bring both the threads into one line) appears to be in the same line exactly you are then immediately to set the Watch, not precisely to the hour of 12 but by so much less, as is the Equation of the day by the Table." Huygens

http://adcs.home.xs4all.nl/Huygens/06/kort-E.html

So what readers have is one 24 hour day following the next 24 hour day, Monday turning into Tuesday,Tuesday into Wednesday and so on with the fact that each day corresponds to one rotation. The average 24 hour day then substitutes for the notion that the Earth's rotation is constant at a rate of 1 Degree per 4 minutes, 15 Degrees per hour and a rotation of the planet's 24901 circumference in 24 hours including the February 29th rotation.