diff --git a/htdocs/holiday/index.php b/htdocs/holiday/index.php
index 1c27e2978bf..26188e1e35d 100644
--- a/htdocs/holiday/index.php
+++ b/htdocs/holiday/index.php
@@ -26,6 +26,7 @@
 require('../main.inc.php');
 require_once DOL_DOCUMENT_ROOT.'/core/class/html.form.class.php';
 require_once DOL_DOCUMENT_ROOT.'/core/class/html.formother.class.php';
+require_once DOL_DOCUMENT_ROOT.'/core/lib/date.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/user/class/user.class.php';
 require_once DOL_DOCUMENT_ROOT.'/user/class/usergroup.class.php';
 require_once DOL_DOCUMENT_ROOT.'/holiday/common.inc.php';
diff --git a/htdocs/holiday/month_report.php b/htdocs/holiday/month_report.php
index f581375463b..b581a3b5bfd 100644
--- a/htdocs/holiday/month_report.php
+++ b/htdocs/holiday/month_report.php
@@ -26,6 +26,7 @@ require('../main.inc.php');
 require_once DOL_DOCUMENT_ROOT.'/user/class/user.class.php';
 require_once DOL_DOCUMENT_ROOT.'/core/class/html.form.class.php';
 require_once DOL_DOCUMENT_ROOT.'/core/class/html.formother.class.php';
+require_once DOL_DOCUMENT_ROOT.'/core/lib/date.lib.php';
 require_once DOL_DOCUMENT_ROOT.'/holiday/common.inc.php';
 
 // Protection if external user