% Horizontal sundial at Greenwich latitude
% Copyright (c) Christian Obrecht, 2010

@sundial.euk

box -10, -2, 10, 18
O = point(0,0)
p = 51 + 28/60 + 38/3600
l = 4

for h = -90 to 90 step 15
  draw time_line(p, h) half
end

draw red
  zodiacal_hyperbola(l, p, 23.44)
  zodiacal_hyperbola(l, p, 20.15)
  zodiacal_hyperbola(l, p, 11.47)
  equinoctial_axis(l, p)
end

for h = -75 to 75 step 15
  draw (equation_of_time(l, p, h)) blue
end
