Index: wp-includes/taxonomy.php
===================================================================
--- wp-includes/taxonomy.php	(revision 11001)
+++ wp-includes/taxonomy.php	(working copy)
@@ -653,7 +653,7 @@
 	$key = md5( serialize( compact(array_keys($defaults)) ) . serialize( $taxonomies ) . $filter_key );
 	$last_changed = wp_cache_get('last_changed', 'terms');
 	if ( !$last_changed ) {
-		$last_changed = time();
+		$last_changed = current_time('timestamp');
 		wp_cache_set('last_changed', $last_changed, 'terms');
 	}
 	$cache_key = "get_terms:$key:$last_changed";
@@ -1836,7 +1836,7 @@
 		delete_option("{$taxonomy}_children");
 	}
 
-	wp_cache_set('last_changed', time(), 'terms');
+	wp_cache_set('last_changed', current_time('timestamp'), 'terms');
 
 	do_action('clean_term_cache', $ids, $taxonomy);
 }