Is it Stroud? There was a programme on Radio 4 about it the other day and I think this was mentioned, something to do with the trains running from London, when the line was built by Brunel and the timetables having a different arrival time, so they had to change it, but a clock still stands there with the local time on it.
It was Open Country on Saturday at 6.30 am. You can hear it if you go to the bbc radio 4 website. Here is a bit from the bbc site:
At the Sapperton Tunnel Ian tells of the end of 'Stroud time' Before 1845 Stroud set its time by the sun. Being some 90 miles west of the meridian, the clocks in Stroud struck noon a few minutes after they did in London. This meant that commuters missed their trains, which were running on London time. In 1858, a new clock set to Railway time was installed in Stroud and can be seen today at Stroud Library. Eventually Stroud had to adopt GMT like everyone else.