Tag Archives: Equation of time

Applying the Equation of Time when calculating longitude at the Sun’s Meridian Passage.

Author’s Note:  The original issue of this post was found to contain errors which have now been corrected.  Many thanks to Jeremy Parker for bringing the errors to my attention. Although the imaginary Mean Time gives us an accurate measurement … Continue reading

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Converting GMT To GHA

Greenwich Mean Time (GMT) is the local mean time anywhere on the meridian of Greenwich.  In other words it is the Local Hour Angle of the Mean Sun on the meridian of Greenwich. Since the Greenwich meridian is used as the … Continue reading

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What Is The Equation of Time

The Sun as a Time-Keeper.  Because the Earth’s orbital motion is not uniform, there are corresponding variations in the apparent speed of the Sun as it travels round the earth.   For this reason, the true Sun (the Sun that we … Continue reading

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