Accurate Solar Time Sundial Installed in a North London Garden

Accurate Solar Time sundial installed and set up at the exact time of local Noon

The sundial is in our client’s garden in North London. The sundial faces due south. We set it up at Noon on 28 November, using accurate corrections for the Equation of Time and local Longitude. The photo shows Solar Time at 12.30pm.

The world of solar time has fascinating ideas to explore. Our accurate sundial is almost a compendium of what a sundial can do. The client’s wish was something special for their newly created garden, and our design of a vertical sundial display appealed to them. We named the sundial Solar Time and completed the installation in North London on 28 November.

The steps to installation begin with a firm fixing at ground level for the sundial pillar, and finish with setting the alignment of the dial to face due south. We set a sundial by the sun. Knowing the exact difference between Solar Time and Greenwich Mean Time (GMT) at the location of the garden on the date of 28 November, we turned the dial to give the correct time reading and locked it there. It is essential for setting the sundial to have bright sunshine, as the picture shows. We had to wait many days for clear blue skies.

On the dial, the vertical line at the centre is Noon. The additional hour lines run from 9am to 2pm. These are solar hours, which follow the movements of the sun. The Analemma loop makes a correct adjustment from solar time to clock time. The prominent lines of dots show half-hour and ten-minute intervals. The dotted line at the top is Winter Solstice, and Summer Solstice is the one at the bottom. Spring and Autumn Equinox fall at the year’s turning point between longer and shorter days. The dial shows length of day.