As usual I have to explain something most are uncomfortable with while knowing all too well that others can't do it because of some silly allegiance to mistakes made centuries ago.

The 24 hour weekday is anchored in noon when the observer is midway to either side of the circle of illumination or ,in geocentric terms, the Sun crosses the observer's meridian. The milestones of each weekday rotation are sunrise, noon, sunset and midnight so that on the September Equinox the Sun rises at 6 AM and sets at roughly 6 PM. Because of DST, sunrise is at 7 AM while Sunset is at 7 PM so this period is the artificial setup.

The creation of the average 24 hour day is also anchored to noon along with the same principles which create the daily milestones of sunrise, noon ect.. The Equation of Time is the facility by which we get the 24 hour day which allows for the flexibility of DST among others things.