Standard Time Zones & Local Mean Time

[David Patte]

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?