Show past events on event category pages

past-events-on-categories.php

function tribe_set_default_date( $wp_query ) {
	// Only run on main event queries
	if ( ! tribe_is_event_query() || ! $wp_query->is_main_query() || $wp_query->get( 'eventDate' ) != '') return;

	// Set this to the date you want shown, in YYYY-MM-DD format
	$date = '2000-01-01';

	// Select which TEC views you want this to apply to by uncommenting them
	if (
		   tribe_is_event_category()
//		|| tribe_is_map()
//		|| tribe_is_photo()
//		|| tribe_is_month()
//		|| tribe_is_week()
//		|| tribe_is_day()
	) {
		$wp_query->set( 'eventDate', $date );
	}
}
if ( function_exists('tribe_is_event_query') ) {
	add_action( 'parse_query', 'tribe_set_default_date', 100);
}
/*
 * Sets the date search value to never be blank
 */
function tribe_bar_set_date_val( $filters ) {
	global $wp_query;
	$new_val = 'value="' . esc_attr( $wp_query->get( 'eventDate' ) ) . '"';
	$filters['tribe-bar-date']['html'] = preg_replace( '/value="[^"]*"/', $new_val, $filters['tribe-bar-date']['html'] );
	return $filters;
}
add_filter( 'tribe-events-bar-filters',  'tribe_bar_set_date_val', 100, 1 );