Moving a country from solar time to unified time is no easy matter (France had three separate kinds of time at one point). However, the railways made it a necessity: local time, which varied by minutes as one travelled east or west, was not really compatible with accurate railway timetables. Noon in Bristol, for example, is over ten minutes later than noon in London.When the Great Western Railway came to Bristol in 1841, it brought 'railway time' with it.
Bristolians had other reasons for wanting to know Greenwich Mean Time as accurately as local time. As a major seafaring port (it traded with America and the Caribbean, and was heavily connected to the slave trade), the city had plenty of people who needed GMT in order to calculate longitude and thus navigate accurately on the oceans. And in 1852, the electric telegraph arrived - with Bristol time creating the ridiculous situation of messages from London apparently arriving before they were sent. Within a few months, the city's public clocks moved from local time to GMT.
Today, few of us tell the time by the sun, so we don't notice the discrepancies between solar noon and the time on our clocks. For those who lived through the transition, though, the clock on Bristol's Corn Exchange with its two minute hands must have been very helpful. Installed in 1822 with just one minute hand set to local time, it was later given a second set to GMT. Only when the city' time was unified in 1852 was the Bristol hand removed; it was finally restored in 1989.