Heritage: Southampton is 6 minutes slower…

Heritage: Southampton is 6 minutes slower…

By Martin Brisland

Did you know that a Southampton sundial will always be six minutes slower than GMT or 1 hour 6 minutes slower than BST?

Robert Morden’s map for Hampshire from circa 1695 is rather interesting. You can easily find it via Google.

Along the bottom you will see a scale in minutes and seconds. It starts at Greenwich, south east London, which is zero. The map shows that Southampton is about a one and a half degrees of arc from Greenwich.

The earth rotates around the sun such that it moves 360 degrees in 24 hours or 15 degrees in one hour. This means that it travels 1 degree in one 15th of an hour which is four minutes.

Southampton is about 1 degree 30 minutes from Greenwich. This means that when the sun is directly over the Greenwich meridian at noon the local time in Southampton is 11.54am, that is 6 minutes behind Greenwich. That is how long it takes for the sun to travel and be directly overhead in Southampton. A sundial that could show local time precisely will always be 6 minutes slower than local time in Greenwich. There is still a sundial on the south side of our Bargate.

The arrival of the railways from about 1840 and the production of timetables required the introduction of standard time which in the UK is Greenwich Meridian Time (GMT). The UK makes an hour adjustment for British Summer Time (BST).


  • In Common is not for profit. We rely on donations from readers to keep the site running. Could you help to support us for as little as 25p a week? Please help us to carry on offering independent grass roots media. Visit: https://www.patreon.com/incommonsoton


You may also like:

Heritage: why are people from Southampton called Sotonians?

Heritage: Legacy of the Spanish Civil War

Heritage: Southampton and the demon drink