Permalink Submitted by Anonymous on August 7, 2010

This was an excellent article, providing all the information needed to design a great sundial. I was able to take the equations and construct an excel spreadsheet that constructs a graph chart image for an analemmatic sundial with just the input of the latitude and longitude of the location for which the sundial is to be designed. I added the ability to change the hour locations around the dial slightly to account for the differences between solar noon and standard time noon (I used longitude to do this calculation, so in areas where the time zones are highly erratically drawn, it is not accurate, but works well for most places). The graph chart also plots out the analemmatic gnomon position based on date along the vertical centerline. From all this, I was able print out the graph chart and use spray adhesive to fix it to a sheet of 1/8" copper. I then used punches and a hammer to mark out the sundial. I also etched an equation of time analemma chart onto the copper surface. The result is a beautiful copper analemmatic sundial that is custom designed for my exact location on earth andd from which the true accurate standard time can be read whenever there is sun.

## analemmatic sundial

This was an excellent article, providing all the information needed to design a great sundial. I was able to take the equations and construct an excel spreadsheet that constructs a graph chart image for an analemmatic sundial with just the input of the latitude and longitude of the location for which the sundial is to be designed. I added the ability to change the hour locations around the dial slightly to account for the differences between solar noon and standard time noon (I used longitude to do this calculation, so in areas where the time zones are highly erratically drawn, it is not accurate, but works well for most places). The graph chart also plots out the analemmatic gnomon position based on date along the vertical centerline. From all this, I was able print out the graph chart and use spray adhesive to fix it to a sheet of 1/8" copper. I then used punches and a hammer to mark out the sundial. I also etched an equation of time analemma chart onto the copper surface. The result is a beautiful copper analemmatic sundial that is custom designed for my exact location on earth andd from which the true accurate standard time can be read whenever there is sun.