This is an unusual clock.

It’s got four hands. There are two hour hands, one red, one black. It will be particularly useful if you often need to know the time in two different parts of the world – perhaps the time in another office, or of a friend who lives abroad.

You can buy this 24 hour clock from Franklin Clocks.

It wouldn’t be as easy to do this with a 12 hour clock face. If, for example, the black hand was pointing to 8 on a 12 hour face, and the red hand pointed to 2, you couldn’t tell whether the red hand was 6 hours earlier than the black one or ahead of it.

There are interesting parallels between this clock and a few clocks that were built in the 19th century during the early days of the railway network’s rapid expansion. At Bristol Corn Exchange, for example, a clock with two minute hands was installed during the 1840s.

One hand indicated the time in London, the time that Brunel’s Great Western Railway kept. The other minute hand showed local time, 11 minutes slower, as kept by Bristolians.

Then, the concern was with the time kept in another town. Now, we’re interested in the time on the other side of the world.