This is the clock on the front of the world famous Corn Exchange in Bristol (source of the well known phrase 'cash on the nail' - but that's another story). Take a look at the clock. Nothing remarkable about it, I think you'll agree. If you were looking at it in real life however, you'd notice that rather than an hour hand, minute hand and second hand, it's actually equipped with two minute hands, each set 9 minutes apart.
These reflect the difference between Bristol time and London time - Bristol being 200km due west of London the sun rises and sets nine minutes later than it does in London. Keeping different times was fine until the coming of the railway, when it soon became apparent that agreement would have to be reached on exactly when trains arrived and departed. Thus began the concept of Greenwich Mean Time.
Apparently we can thank Isambard Kingdom Brunel - another famous Bristolian - for correcting this rather irritating anomaly. I imagine his conversation with the Minister for Clocks And Stuff would have gone something like this:
Isambard: Ere, me babber. 'Ave youw notessed thaat when youw catch ther trainl from Lundun to Bressle, yer waaaatch ends up noine menets faasrt?
Minister: What's that, old chap? Didn't quite catch it on account of the rather poor Vicki Pollard impression.
Isamabard: Sorry moi lurve. Carn't 'elp 'et. I's frum Bressle, see. Waaatch faarst 'en Bressle.
Minister: Watch? Fast? Bristol? What are you whittering about man? By the way old chap, I've noticed that my watch is always 9 minutes fast whenever I take a jaunt to bristol. Go and sort it out for us, there's a good fellow.
Isambard: Cheers then, Drive. Sorry. Thaat were outta 'abit. I gotta ideal. Frum now on, all ther clarks in Bressle be put ferwerd noine menets so they's ther same as Lundun's. Prublem sulved.
Minister: Splendid. Now tell my why you have such a strange name...
There ya go.