File Source for mod_calendar.php

<?php
/**
* @version $Header$
* @package calendar
* @subpackage modules
*/
/**
* Required setup
*/
include_once( CALENDAR_PKG_PATH.'Calendar.php' );
$cal = new Calendar();
// set up the todate
if( !empty( $_REQUEST['todate'] ) ) {
// clean up todate. who knows where this has come from
/* if ( is_numeric( $_REQUEST['todate'] ) ) {
$_SESSION['calendar']['focus_date'] = $_REQUEST['todate'] = $cal->mDate->gmmktime( 0, 0, 0, $cal->mDate->date( 'm', $_REQUEST['todate'] ), $cal->mDate->date( 'd', $_REQUEST['todate'] ), $cal->mDate->date( 'Y', $_REQUEST['todate'] ) );
} else {
$_SESSION['calendar']['focus_date'] = $_REQUEST['todate'] = $cal->mDate->gmmktime( 0, 0, 0, $cal->mDate->date2( 'm', $_REQUEST['todate'] ), $cal->mDate->date2( 'd', $_REQUEST['todate'] ), $cal->mDate->date2( 'Y', $_REQUEST['todate'] ) );
} */
} elseif( !empty( $_SESSION['calendar']['focus_date'] ) ) {
$_REQUEST["todate"] = $_SESSION['calendar']['focus_date'];
} else {
$_SESSION['calendar']['focus_date'] = $cal->mDate->gmmktime( 0, 0, 0, $cal->mDate->date( 'm' ), $cal->mDate->date( 'd' ), $cal->mDate->date( 'Y' ) );
$_REQUEST["todate"] = $_SESSION['calendar']['focus_date'];
}
$calHash = array(
'focus_date' => $_SESSION['calendar']['focus_date'],
'view_mode' => 'month',
);
$cal->setupCalendar(FALSE);
$_template->tpl_vars['modCalNavigation'] = new Smarty_variable( $cal->buildCalendarNavigation( $calHash ) );
$_template->tpl_vars['modCalMonth'] = new Smarty_variable( $calMonth = $cal->buildMonth( $calHash ) );
?>

Source for file mod_calendar.php