--- signup/includes/date.inc.orig	2010-01-21 20:03:38.000000000 +0000
+++ signup/includes/date.inc	2010-01-21 20:05:12.000000000 +0000
@@ -453,10 +453,10 @@
     case 'pgsql':
       $granularity .= 'S';
       if ($direction == 'ADD') {
-        return "($field + INTERVAL '$count $granularity')";
+        return "($field + INTERVAL '1 $granularity' * $count)";
       }
       else {
-        return "($field - INTERVAL '$count $granularity')";
+        return "($field - INTERVAL '1 $granularity' * $count)";
       }
   }
   return $field;