diff --git a/htdocs/setup.php b/htdocs/setup.php
index 91857795..cab10895 100644
--- a/htdocs/setup.php
+++ b/htdocs/setup.php
@@ -127,6 +127,15 @@ include("page-header.php");
 
 require_once("AwlQuery.php");
 
+
+function check_datetime() {
+  if ( class_exists('DatexTime') ) return new CheckResult(true);
+  $result = new CheckResult(false);
+  $result->setClass('dep_warning');
+  $result->setDescription(i18n('Most of DAViCal will work but upgrading to PHP 5.2 or later is strongly recommended.'));
+  return $result;
+}
+
 function check_schema_version() {
   global $c;
   if ( $c->want_dbversion[0] == $c->schema_major
@@ -217,10 +226,12 @@ function build_dependencies_table( ) {
     translate('PDO PostgreSQL drivers')           => 'check_pdo_pgsql',
     translate('PHP PostgreSQL available')         => 'check_pgsql',
     translate('GNU gettext support')              => 'check_gettext',
+    translate('PHP iconv support')                => 'check_iconv',
+    translate('PHP DateTime class')               => 'check_datetime',
     translate('Suhosin "server.strip" disabled')  => 'check_suhosin_server_strip',
     translate('PHP Magic Quotes GPC off')         => 'check_magic_quotes_gpc',
     translate('PHP Magic Quotes runtime off')     => 'check_magic_quotes_runtime'
-  );
+    );
   
   $dependencies_table = '';
   $dep_tpl = '<tr class="%s">