These are complex questions, hinging on subjective interpretations of the terms involved, such as "general acceptance". The book "Greenwich Time and Longitude", by Derek Howse, has a lot of information about standard time in Great Britain. For example, he writes (pp. 114-15) that in 1858, a court decided that legal time "must be understood as the mean time at the place where" an event occurs, "and not Greenwich time, unless it be so expressed." Prior to that, there had been "nothing on the statute book to define what was the time for legal purposes" -- but at that date "98% of the public clocks in Great Britain were set to GMT." On August 2, 1880, it finally became law that "[w]henever any expression of time occurs in any Acts of Parliament, deed, or other legal instrument, the time referred shall, unless it is otherwise specifically stated, be held in the case of Great Britain to be Greenwich mean time, and in the case of Ireland, Dublin mean time." (Copyrighted material, quoted under fair use.) So perhaps that answers part of your inquiry. You may have to hit the books in a good library if you want more complete answers. Gwillim Law ----- Original Message ----- From: "David Patte" <dpatte@relativedata.com>
Does anyone have insight into the dates when standard timezones, based from Greenwich and at 15 degree intervals (as are still used in international waters) started coming into general acceptance or law? Am I correct to assume that the first place to use 'standard time' was Britain in 1847, but that the international acceptance of a 'world' timezone system based on GMT offsets only really started with Sir Andrew Fleming's proposals in 1879?
Also, before that, when did 'mean time' as opposed to 'solar time' start coming into general acceptance? I read that it was when accurate mechanical clocks started becoming available in the early 1800s. Anyone have an approximate date for first adoption of mean time by a city?