Jovaro, it doesn't seem to matter how many times something is explained to you, you don't get it, so I have given up and encourage you go please, please go learn.
One note, however, if the simple fact the error margins were larger in the past explains the speed of light data, then WHY are ALL the measurements, regardless of error margins, showing a downward trend toward what the speed of light is now? If the speed of light has always been constant as per time between emission and final absorption, then we would expect the measurements to be on both sides of that speed, but they are not.
The statistical verification for the changing speed of light measurements can be found here:
http://www.setterfield.org/data.htm
And, one more time, the LENGTH of a second or a day has NOTHING to do with our calendar system! It is the time it takes the moon to go around the earth and the earth to go around the sun which are the key things. The FACT that the earth turns on its axis is what makes day and night. The length of a day and night even changes with the seasons! So that is not an issue, let alone the length of an hour or a second!