Index: uc_roles/uc_roles.module
===================================================================
--- uc_roles/uc_roles.module	(revision 988)
+++ uc_roles/uc_roles.module	(working copy)
@@ -1370,7 +1370,8 @@
       $end_time = mktime(0, 0, 0, $end_time['month'], $end_time['day'], $end_time['year']);
     }
 
-    return $end_time;
+    // Avoid year 2038 bug.
+    return ($end_time > 2147483647 || $end_time == 0) ? 2147483647 : $end_time;
   }
 }
 
@@ -1397,5 +1398,7 @@
   $start_time = (!is_null($start_time)) ? $start_time : time();
   $operator = ($duration < 0) ? '' : '+';
 
-  return strtotime($operator . $duration .' '. $granularity, $start_time);
+  $end_time = strtotime($operator . $duration .' '. $granularity, $start_time);
+  // Avoid Year 2038 bug.
+  return ($end_time > 2147483647 || $end_time == 0) ? 2147483647 : $end_time;
 }