<sect2 id="calc-equinox"> <title>Equinoxes and Solstices module</title> <indexterm><primary>Tools</primary> <secondary>Astrocalculator</secondary> <tertiary>Equinoxes and Solstices module</tertiary> </indexterm> <screenshot> <screeninfo> The Equinoxes and Solstices calculator module </screeninfo> <mediaobject> <imageobject> <imagedata fileref="calc-equinox.png" format="PNG"/> </imageobject> <textobject> <phrase>Equinoxes and Solstices</phrase> </textobject> </mediaobject> </screenshot> <para> The <link linkend="ai-equinox">Equinoxes</link> and Solstices module calculates the date and time of an equinox or solstice for a given year. You specify which event (Spring Equinox, Summer Solstice, Autumn Equinox, or Winter Solstice) should be investigated, and the year. Then press the <guibutton>Compute</guibutton> button to obtain the date and time of the event, and the length of the corresponding season, in days. </para> <para> There is a batch mode for this module. To use it, simply generate an input file whose lines each contain a year for which the Equinox and Solstice data will be computed. Then specify the input and output filenames, and press the <guibutton>Run</guibutton> button to generate the output file. Each line in the output file contains the input year, the date and time of each event, and the length of each season. </para> </sect2>