The angles
z of the hour lines are computed by the formula:
tan(z) =
sin(φ) · tan(τ+∆φ)
φ = latitude, τ = hour angle, τ=n·15°, ∆φ is the deviation from the time zone meridian Instructions
then hit the button "Apply
input"
Example:
51,5°
North
und
8°
East This
sundial
is
made
of
brass:

Updated:
2013, Feb 13