<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>