WordPress: Thoughts on Filtering by Time

anonymous.php

<?php
$age_filter = function ( $where = '' ) use ( $options ) {
	$where .= " AND post_date > '" . date( 'Y-m-d', strtotime( '-' . $options[ 'max_post_age' ] ) ) . "'";
	return $where;
};

add_filter( 'posts_where', $age_filter );
$query = new WP_Query( $args );
remove_filter( 'posts_where', $age_filter );

codex.php

<?php
function filter_where( $where = '' ) {
	$where .= " AND post_date > '" . date( 'Y-m-d', strtotime( '-30 days' ) ) . "'";
	return $where;
}

add_filter( 'posts_where', 'filter_where' );
$query = new WP_Query( $args );
remove_filter( 'posts_where', 'filter_where' );

single.php

<?php
/**
 * Wrap a block of code in a WordPress filter.
 *
 * That filter is added before the block is called and removed after it.
 * 
 * @param  string $filter_tag    WordPress filter tag.
 * @param  function $filter_func The filter function.
 * @param  function $block       The code to be wrapped in the filter.
 * @return mixed                 Result of the called block.
 */
function with_filter( $filter_tag, $filter_func, $block ) {

	add_filter( $filter_tag, $filter_func );
	$result = call_user_func( $block );
	remove_filter( $filter_tag, $filter_func );

	return $result;
}

$query = with_filter(
	'posts_where',
	function ( $where = '' ) use ( $options ) {
	  $where .= " AND post_date > '" . date( 'Y-m-d', strtotime( '-' . $options[ 'max_post_age' ] ) ) . "'";
	  return $where;
	}, function () use ( $args ) {
		return new \WP_Query( $args );
	}
);