WordPress at a glance
function is not described

wp_ajax_date_format() WP 3.1.0

Ajax handler for date formatting.

No Hooks.

Return

Nothing (null).

Usage

wp_ajax_date_format();

Code of wp ajax date format: wp-admin/includes/ajax-actions.php VER 5.0.3

<?php
function wp_ajax_date_format() {
	wp_die( date_i18n( sanitize_option( 'date_format', wp_unslash( $_POST['date'] ) ) ) );
}