Correct version 2 of Solar Watch, or portable "Cadran du Berger" (dial's shepherd) used since at least 1867 in the Pyrenees.

Rendering STRATA; 3D MoI

Some explanations: As it has been observed that the hours, 3am/pm & 9am/pm coincide at certain points of the year, a first simplification was made on a single line; that create negligible inexactitudes of only few minutes certain days.

Other simplification: as the days are almost identical 2 by 2, the vertical lines of days will be reduced; the June 21 being the longest day, its line will be the axis of days. The shadow variations, on a small size object (2cm x 8cm) are not significant, so the watch of shepherd uses only 1 vertical line for 10 consecutive days; that gives just 19 vertical lines for all the days in 1 year.

True Time is Happiness; in french: "Bonne heure (good hour) est Bonheur (goodhour)".