WordPress: Display archive links based on type and format. Uses the built in wp_get_archives() but with added filters to display archive only for a specific year, month or day

wp_get_archives_specific.php

<?php
/**
 * Display archive links based on type and format. Uses the built in wp_get_archives() but with
 * added filters to display archive only for a specific year, month or day
 * @param string|array $args Optional. Override defaults.
 * @param null|int $year Specify year for archive
 * @param null|int $month Specify month for archive
 * @param null|int $day Specify day for archive
 * @return string|void Return or echo depending on "echo" argument
 * @author David M&aring;rtensson <david.martensson@gmail.com>
 */
function wp_get_archives_specific($args='', $year=null, $month=null, $day=null) {
	$default = array(
		'_specific_year' => null,
		'_specific_month' => null,
		'_specific_day' => null	
	);
	$r = wp_parse_args($args, $default);
	
	if (!is_null($year)) {
		$r['_specific_year'] = $year;
	}
	if (!is_null($month)) {
		$r['_specific_month'] = $month;
	}
	if (!is_null($day)) {
		$r['_specific_day'] = $day;
	}
	if (!is_null($year) || !is_null($month) || !is_null($day)) {
		add_filter('getarchives_where', '__filter_wp_get_archives_specific', 10, 2);
	}
	
	$org_echo = (isset($args['echo']) ? $args['echo']:1);
	$r['echo'] = 0;
		
	$archive = wp_get_archives($r);
	
	remove_filter('getarchives_where', '__filter_wp_get_archives_specific');
	
	if ($org_echo) {
		echo $archive;
	}
	else {
		return $archive;
	}
}

/**
 * Filter function used by wp_get_archives_specific() and the filter "getarchives_where"
 * @param string $where
 * @param string|array
 * @return string
 * @author David M&aring;rtensson <david.martensson@gmail.com>
 */
function __filter_wp_get_archives_specific($where, $args) {
	global $wpdb;
	if (isset($args['_specific_year']) && !empty($args['_specific_year'])) {
		$where .= " AND YEAR(post_date) = '".$wpdb->escape($args['_specific_year'])."'";
	}
	if (isset($args['_specific_month']) && !empty($args['_specific_month'])) {
		$where .= " AND MONTH(post_date) = '".$wpdb->escape($args['_specific_month'])."'";
	}
	if (isset($args['_specific_day']) && !empty($args['_specific_day'])) {
		$where .= " AND DAY(post_date) = '".$wpdb->escape($args['_specific_day'])."'";
	}
	return $where;
}