> Noon should be whatever noon's offset from UTC should be. I presume one wants a fixed offset / a fixed 24h day (modulo leap days). (The length of a day chang

> Noon should be whatever noon's offset from UTC should be. I presume one wants a fixed offset / a fixed 24h day (modulo leap days). (The length of a day changes during the year. And I mean in the sense of "the time between high noon on one day to the next" changes, not the amount of sunlight, which of course changes. This is what the "mean" in "mean solar time" is: https://en.wikipedia.org/wiki/Solar_time#Apparent_solar_time https://en.wikipedia.org/wiki/Solar_time#Apparent_solar_time)