Sundials are literally as old as time. Age-old mysteries and wonders inherent in the movement of sun-shadows echo in them. No one knows when man first learned to tell time, but the sundial art was developed by the ancient Egyptians, Babylonians and Greeks.
Sundial pendants have been worn on clothing for thousands of years to tell the time.
Did you know that time as measured by the Sun is only accurate 4 days per year! That is why we have Greenwich Mean Time; where Mean = "average" and is the average length of the day as measured by the Sun at Greenwich, England.
Your sundial can be up to 16 minutes out and the average sundial will need a conversion table!
A most interesting Thames Sundial Trail goes from the Houses of Parliament (Big Ben) down the River Thames through Greenwich to the Thames Barrier. This route takes in some of the best views of London, the capital of the UK.
Another shorter route is the Sundial Trail at the Horniman Museum, in London too.
The UK Sundial site