Zefram wrote:
In the above, I'm using the term "country" as a synonym for "ISO 3166 region", by which I mean a region to which ISO 3166 assigns a regular alpha-2 code. I think this is uncontroversial ground on this list, but worth explicating in this context: the biggest political question we're ducking is what constitutes a country.
Looking at the genealogical data, country boundaries change over time, so we can not rely on the current map of the world if the job is to be done correctly. No doubt in the future some areas will move from one time zone to another due to 'political' changes. Being practical, clocks were not being used widely before the 1700s, but prior to that time was actually quite 'accurate' based on the sundial, so much so that clocks set to local time then demonstrated the error across countries. 'Midday' in historic records can be reliably determined for any where on the world on any date but I think for now simply aiming to reflect the creation of time zones back in 1884 should be a starting point? -- Lester Caine - G8HFL ----------------------------- Contact - http://lsces.co.uk/wiki/?page=contact L.S.Caine Electronic Services - http://lsces.co.uk EnquirySolve - http://enquirysolve.com/ Model Engineers Digital Workshop - http://medw.co.uk Rainbow Digital Media - http://rainbowdigitalmedia.co.uk