diff --git a/wp-admin/options-general.php b/wp-admin/options-general.php
index 48d0bdf71d..541980d0c1 100644
--- a/wp-admin/options-general.php
+++ b/wp-admin/options-general.php
@@ -232,10 +232,11 @@ if ( empty($tzstring) ) { // Create a UTC+- zone if no timezone string exists
 	* Filter the default date formats.
 	*
 	* @since 2.7.0
+	* @since 4.0.0 Added ISO date standard YYYY-MM-DD format.
 	*
 	* @param array $default_date_formats Array of default date formats.
 	*/
-	$date_formats = array_unique( apply_filters( 'date_formats', array( __( 'F j, Y' ), 'Y/m/d', 'm/d/Y', 'd/m/Y' ) ) );
+	$date_formats = array_unique( apply_filters( 'date_formats', array( __( 'F j, Y' ), 'Y/m/d', 'm/d/Y', 'd/m/Y', 'Y-m-d' ) ) );
 
 	$custom = true;