<sect2 id="calc-sidereal"> <title>Sidereal Time module</title> <indexterm><primary>Tools</primary> <secondary>Astrocalculator</secondary> <tertiary>Sidereal Time module</tertiary> </indexterm> <screenshot> <screeninfo> The Sidereal Time calculator module </screeninfo> <mediaobject> <imageobject> <imagedata fileref="calc-sidereal.png" format="PNG"/> </imageobject> <textobject> <phrase>Sidereal Time</phrase> </textobject> </mediaobject> </screenshot> <para> This module converts between <link linkend="ai-utime">Universal Time</link> and Local <link linkend="ai-sidereal">Sidereal Time</link>. First, select whether you will use Universal Time or Sidereal Time as an input value in the <guilabel>Input Selection</guilabel> section. You must also specify a geographic longitude, and a date for the calculation, in addition to either the Universal Time or the Sidereal Time value. When you press the <guibutton>Compute</guibutton> button, the corresponding value for the other Time will be displayed. </para> </sect2>