<sect2 id="calc-dayduration"> <title >Day Duration module</title> <indexterm ><primary >Tools</primary> <secondary >Astrocalculator</secondary> <tertiary >Day Duration module</tertiary> </indexterm> <screenshot> <screeninfo >The Day Duration calculator module </screeninfo> <mediaobject> <imageobject> <imagedata fileref="calc-daylength.png" format="PNG"/> </imageobject> <textobject> <phrase >Day Duration</phrase> </textobject> </mediaobject> </screenshot> <para >This module computes the length of day as well as sunrise, sun-transit (noon), and sunset times for any calendar date, for any location on Earth. First fill in the desired geographic coordinates and date, then press the <guibutton >Compute</guibutton > button. </para> </sect2>