That's because our official time keeping is done by means of the "mean sun" rather than the "true sun".
"Now, the variations in the true Sun's motion causes it to sometimes be ahead of, sometimes lag behind, and sometimes be neck and neck with the mean Sun."
Also, because Daylight Savings Time really throws things off around here.
I was thinking of switching to solar noon.
I planned to do it very soon.
I bought a super precise sun dial,
But late at night, it's not worthwhile.