Moondials

The above Moondial works using the 19 year Metonic Cycle of the Moon The Golden Number is given in the pie chart to the left and when the appropriate number is applied to the Golden Date, given in the centre of the dial, the phase and age of the Moon is revealed for every date between 2000 and 2132 AD The sundial is also a solar calendar It is possible to calculate tidal information from this device A site specific and longitude corrected sundial is also displayed along with the Equation of Time expressed as an integer around the calendar for every day of the year Using the calculations given in the Moondial chart the sundial will not only read time accurately in sunlight but also tell time at night, by moonlight

Such Moondial instruments have been known from at least the late 1500's and probably much earlier

Triple Dial, Armillary Sundial, Armillary Spheres, Horizontal Sundials, Noon Cannons, Favourites, Astrolabe, Moondials, Antarctica Sundial or Horizontal Projection Instrument