WordPress at a glance
filter is not described

get_calendar filter-hook . WP 3.0.0

Filters the HTML calendar output.

Usage

add_filter( 'get_calendar', 'filter_function_name_5239' );
function filter_function_name_5239( $calendar_output ){
	// filter...

	return $calendar_output;
}
$calendar_output(string)
HTML output of the calendar.

Where the hook is called

get_calendar()
get_calendar
wp-includes/general-template.php 2136
echo apply_filters( 'get_calendar', $calendar_output );
wp-includes/general-template.php 1937
$output = apply_filters( 'get_calendar', $cache[ $key ] );
wp-includes/general-template.php 2140
return apply_filters( 'get_calendar', $calendar_output );

Where the hook is used (in WP core)

Does not used.