diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 1fe8c14..a0100c3 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -193,10 +193,12 @@ define('LANGUAGE_RTL', 1);
 /**
  * For convenience, define a short form of the request time global.
  *
- * REQUEST_TIME is a float with microseconds since PHP 5.4.0, but float
- * timestamps confuses most of the PHP functions (including date_create()).
+ * REQUEST_TIME is an integer measuring seconds.
+ * This differs from $_SERVER['REQUEST_TIME'], which is stored as a float
+ * since PHP 5.4.0, because float timestamps confuse most PHP functions
+ * (including date_create()).
  */
-define('REQUEST_TIME', (int) $_SERVER['REQUEST_TIME']);
+ define('REQUEST_TIME', (int) $_SERVER['REQUEST_TIME']);
 
 /**
  * Flag for drupal_set_title(); text is not sanitized, so run check_plain().