This function’s access is marked private. This means it is not intended for use by plugin or theme developers, only in other core functions. It is listed here for completeness.


Die with a maintenance message when conditions are met.


Checks for a file in the ClassicPress root directory named ".maintenance". This file will contain the variable $upgrading, set to the time the file was created. If the file was created less than 10 minutes ago, ClassicPress enters maintenance mode and displays a message.

The default message can be replaced by using a drop-in (maintenance.php in the wp-content directory).


File: wp-includes/load.php

function wp_maintenance() {
	if ( ! file_exists( ABSPATH . '.maintenance' ) || wp_installing() )

	global $upgrading;

	include( ABSPATH . '.maintenance' );
	// If the $upgrading timestamp is older than 10 minutes, don't die.
	if ( ( time() - $upgrading ) >= 600 )

	 * Filters whether to enable maintenance mode.
	 * This filter runs before it can be used by plugins. It is designed for
	 * non-web runtimes. If this filter returns true, maintenance mode will be
	 * active and the request will end. If false, the request will be allowed to
	 * continue processing even if maintenance mode should be active.
	 * @since WP-4.6.0
	 * @param bool $enable_checks Whether to enable maintenance mode. Default true.
	 * @param int  $upgrading     The timestamp set in the .maintenance file.
	if ( ! apply_filters( 'enable_maintenance_mode', true, $upgrading ) ) {

	if ( file_exists( WP_CONTENT_DIR . '/maintenance.php' ) ) {
		require_once( WP_CONTENT_DIR . '/maintenance.php' );


	$protocol = wp_get_server_protocol();
	header( "$protocol 503 Service Unavailable", true, 503 );
	header( 'Content-Type: text/html; charset=utf-8' );
	header( 'Retry-After: 600' );
	<!DOCTYPE html>
	<html xmlns=""<?php if ( is_rtl() ) echo ' dir="rtl"'; ?>>
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
		<title><?php _e( 'Maintenance' ); ?></title>

		<h1><?php _e( 'Briefly unavailable for scheduled maintenance. Check back in a minute.' ); ?></h1>


Version Description
WP-3.0.0 Introduced.