I never thought of that dep't: In 1857, before time zones were invented, every town had its own time.
(Not in Britain, where a more civilized nation had Greenwich posting an agreed-upon time for everyone by 1852...)
It was the railroads that forced a common time to happen. Suddenly there was a need for everyone to understand the same time. The agreed-upon time used to be called "Railroad Time". But people agreed to call it Standard Time. And we still do.
