Altitude Sundials

In the so called high sundials, the main feature is that the marking of hours depends on the height of the sun, that is, the angle at any given time of the day makes the sun with the plane of the horizon. This angle is variable, not only throughout the day obviously, but also in successive days, at same time, and therefore the watch dial will carry an annual calendar that allows us to set the date on which we will make the measurement. These kind of sundials are constructed just for a given latitude, so its accuracy will be lost as we go away from it.