Donald, I can't open your file because I have an older Excel program. But I think to have the solution what you want to do.
You set your watch to local suntime. With that time you are in the field with a sundial. Seen the pictures that is an analemmatic sundial, corrected for longitude. The XII is offset from the line of dates. And I think that is the problem. You need a sundial that gives local suntime, the time you have in your pocket on the watch. Rotate the analemmatic dial until it reads the same time as your watch and you have the North South line. Best wishes, Fer. Fer J. de Vries De Zonnewijzerkring http://www.de-zonnewijzerkring.nl Molens http://www.collsemolen.dse.nl Eindhoven, Netherlands lat. 51:30 N long. 5:30 E ----- Original Message ----- From: Donald Christensen To: sundial@uni-koeln.de Sent: Friday, October 14, 2011 5:10 AM Subject: solar time calculator Not sure what I’m doing wrong I wrote a program so that I can set my watch to solar time. Something is wrong. Either my program is wrong or my sundial is inaccurate. To use the program Set your computer accurately to clock time Run the macro ‘recalc’. This will make the clock on your computer display on the spreadsheet in real time. This will also input today’s date. This date will lookup the EOT and either add or subtract the time Set your watch to solar time The purple cell is for troubleshooting. 1 = add the eot values (positive or negative). -1 will subtract these values. Once I figure out which one to use, it will be true for all days. At the moment, neither work My objective is to make a solar compass that will work for my area only I’ll simply rotate the sundial that I designed with longitude correction until it agrees with my watch that I set to solar time. I understand that the EOT has accuracy problems. However, I thought it was accurate enough for what I want it for. I’d like your feedback on that. I’d also like your feedback on whether or not my goal is realistic in spite of the accumulation of small errors such as eot, sundial accuracy, gnomon placement and gnomon perpendicular to the dial -- Cheers Donald 0423 102 090 This e-mail is privileged and confidential. If you are not the intended recipient please delete the message and notify the sender. Un-authorized use of this email is subject to penalty of law. So there! ------------------------------------------------------------------------------ --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
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