+/**
+ * Schedule core, theme, and plugin update checks.
+ *
+ * @since 3.1.0
+ */
+function wp_schedule_update_checks() {
+ if ( !wp_next_scheduled('wp_version_check') && !defined('WP_INSTALLING') )
+ wp_schedule_event(time(), 'twicedaily', 'wp_version_check');
+
+ if ( !wp_next_scheduled('wp_update_plugins') && !defined('WP_INSTALLING') )
+ wp_schedule_event(time(), 'twicedaily', 'wp_update_plugins');
+
+ if ( !wp_next_scheduled('wp_update_themes') && !defined('WP_INSTALLING') )
+ wp_schedule_event(time(), 'twicedaily', 'wp_update_themes');
+}
+
+if ( ! is_main_site() )
+ return;
+