Erik L. Arneson is a freelance writer and software developer with WordPress experience. He is located in Portland, Oregon. Jekyll 2026-06-18T15:03:10+00:00 https://arnesonium.com/feeds/planetary-hours.xml Erik L. Arneson Erik L. Arneson 2017-05-01T18:30:35+00:00 https://arnesonium.com/2017/05/arduino-planetary-hours-library <p>I am finally announcing my <a href="https://bitbucket.org/arnesonium/planetaryhours">PlanetaryHours library for the Arduino</a>. This library uses the <code class="language-plaintext highlighter-rouge">sun_rise()</code> and <code class="language-plaintext highlighter-rouge">sun_set()</code> functions from the <a href="http://www.nongnu.org/avr-libc/user-manual/group__avr__time.html">avr-libc time.h</a> library to calculate planetary hours.</p> <p><a class="button" href="https://bitbucket.org/arnesonium/planetaryhours/get/v1.0.zip">Download v1.0 Here</a> <!--more--></p> <p>Planetary hours are an old method of figuring out which planets are “in charge” at any moment. For more information on planetary hours, check out these resources:</p> <ul> <li><a href="http://www.renaissanceastrology.com/planetaryhoursarticle.html" target="_blank">http://www.renaissanceastrology.com/planetaryhoursarticle.html</a></li> <li><a href="http://www.esotericarchives.com/agrippa/agripp2c.htm#chap34" target="_blank">http://www.esotericarchives.com/agrippa/agripp2c.htm#chap34</a></li> </ul> <p>You can set up a <code class="language-plaintext highlighter-rouge">PlanetaryHour</code> object by passing it a time zone offset in hours, a latitude, and a longitude. The following example might help.</p> <div class="language-cpp highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="cp">#define MYZONE -7 </span> <span class="n">PlanetaryHour</span> <span class="nf">ph</span><span class="p">(</span><span class="n">MYZONE</span><span class="p">,</span> <span class="mf">45.5</span><span class="p">,</span> <span class="o">-</span><span class="mf">122.7</span><span class="p">);</span> </code></pre></div></div> <p>Then, you can check the ruling planet of the current day and hour with an RTC or other time-keeping mechanism.</p> <div class="language-cpp highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="kt">time_t</span> <span class="n">timer</span> <span class="o">=</span> <span class="n">utc</span><span class="p">.</span><span class="n">unixtime</span><span class="p">()</span> <span class="o">-</span> <span class="n">UNIX_OFFSET</span><span class="p">;</span> <span class="kt">uint8_t</span> <span class="n">dayPlanet</span> <span class="o">=</span> <span class="n">ph</span><span class="p">.</span><span class="n">dayPlanet</span><span class="p">(</span><span class="o">&amp;</span><span class="n">timer</span><span class="p">);</span> <span class="kt">uint8_t</span> <span class="n">hourPlanet</span> <span class="o">=</span> <span class="n">ph</span><span class="p">.</span><span class="n">hourPlanet</span><span class="p">(</span><span class="o">&amp;</span><span class="n">timer</span><span class="p">);</span> </code></pre></div></div> <p>The return value of <code class="language-plaintext highlighter-rouge">dayPlanet()</code> and <code class="language-plaintext highlighter-rouge">hourPlanet()</code> is a number from 0 to 6, corresponding to the Chaldean planetary order.</p> <div class="language-cpp highlighter-rouge"><div class="highlight"><pre class="highlight"><code><span class="cp">#define SATURN 0 #define JUPITER 1 #define MARS 2 #define SUN 3 #define VENUS 4 #define MERCURY 5 #define MOON 6 </span></code></pre></div></div> <p>I’ll be posting an article on <a href="http://www.arnemancy.com/" target="_blank">the Arnemancy blog</a> outlining a project I just installed using this library and some <a href="https://www.adafruit.com/category/168" target="_blank">NeoPixels</a>. I really look forward to seeing what others end up doing with this code!</p> <p><a class="button" href="https://bitbucket.org/arnesonium/planetaryhours/get/v1.0.zip">Download v1.0 Here</a></p>