This dual sundial captures the time of day and the season of the year with two separate gnomons, which cast two separate shadows. In this photo the season gnomon casts its shadow in winter sunshine. The shadow falls at a low angle and crosses a sundial marker for Winter Solstice.
It is always intriguing to see how many different measurements can be made with a sundial, and in how many different ways. The Dihelion sundial measures in two ways, and you wait for a whole year before the measurements repeat themselves, but it is always fascinating. The photo catches a moment of winter sunshine when Dihelion throws a shadow at a shallow angle across a winter solstice marker.
The date of the photo is only thirteen days before midwinter when the sun stands still, and only 1° away from the point when the angle of the shadow starts climbing again as each day the sun rises higher in the sky. Dark winter days are still ahead, but spring days will follow after them. Dihelion was conceived as a sundial measuring time of day and season of the year. It does its work well and even in winter can capture sunshine in a blaze of light.