diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 4ebefbf07ab..238fad5d5cc 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -4326,8 +4326,8 @@ class Form
             $syear = '';
             $smonth = '';
             $sday = '';
-            $shour = empty($conf->global->MAIN_DEFAULT_DATE_HOUR) ? '' : $conf->global->MAIN_DEFAULT_DATE_HOUR;
-            $smin = empty($conf->global->MAIN_DEFAULT_DATE_MIN) ? '' : $conf->global->MAIN_DEFAULT_DATE_MIN;
+            $shour = !isset($conf->global->MAIN_DEFAULT_DATE_HOUR) ? '' : $conf->global->MAIN_DEFAULT_DATE_HOUR;
+            $smin = !isset($conf->global->MAIN_DEFAULT_DATE_MIN) ? '' : $conf->global->MAIN_DEFAULT_DATE_MIN;
         }
 
         $usecalendar='combo';
diff --git a/htdocs/core/tpl/objectline_create.tpl.php b/htdocs/core/tpl/objectline_create.tpl.php
index e1d0a8de1dd..39de2604a0d 100644
--- a/htdocs/core/tpl/objectline_create.tpl.php
+++ b/htdocs/core/tpl/objectline_create.tpl.php
@@ -392,21 +392,21 @@ if ((! empty($conf->service->enabled) || ($object->element == 'contrat')) && $da
 		echo $form->select_date($date_start,'date_start',empty($conf->global->MAIN_USE_HOURMIN_IN_DATE_RANGE)?0:1,empty($conf->global->MAIN_USE_HOURMIN_IN_DATE_RANGE)?0:1,1,"addproduct",1,0,1);
 		echo ' '.$langs->trans('to').' ';
 		echo $form->select_date($date_end,'date_end',empty($conf->global->MAIN_USE_HOURMIN_IN_DATE_RANGE)?0:1,empty($conf->global->MAIN_USE_HOURMIN_IN_DATE_RANGE)?0:1,1,"addproduct",1,0,1);
-	}
+	};
 	print '<script type="text/javascript">';
 	if (!$date_start) {
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_START_HOUR)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_START_HOUR)) {
 			print 'jQuery("#date_starthour").val("'.$conf->global->MAIN_DEFAULT_DATE_START_HOUR.'");';
 		}
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_START_MIN)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_START_MIN)) {
 			print 'jQuery("#date_startmin").val("'.$conf->global->MAIN_DEFAULT_DATE_START_MIN.'");';
 		}
 	}
 	if (!$date_end) {
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_END_HOUR)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_END_HOUR)) {
 			print 'jQuery("#date_endhour").val("'.$conf->global->MAIN_DEFAULT_DATE_END_HOUR.'");';
 		}
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_END_MIN)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_END_MIN)) {
 			print 'jQuery("#date_endmin").val("'.$conf->global->MAIN_DEFAULT_DATE_END_MIN.'");';
 		}
 	}
diff --git a/htdocs/core/tpl/objectline_edit.tpl.php b/htdocs/core/tpl/objectline_edit.tpl.php
index 155ed87724c..a88f1bc210c 100644
--- a/htdocs/core/tpl/objectline_edit.tpl.php
+++ b/htdocs/core/tpl/objectline_edit.tpl.php
@@ -231,18 +231,18 @@ $coldisplay=-1; // We remove first td
 	echo $form->select_date($line->date_end,'date_end',$hourmin,$hourmin,$line->date_end?0:1,"updateligne",1,0,1);
 	print '<script type="text/javascript">';
 	if (!$line->date_start) {
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_START_HOUR)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_START_HOUR)) {
 			print 'jQuery("#date_starthour").val("'.$conf->global->MAIN_DEFAULT_DATE_START_HOUR.'");';
 		}
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_START_MIN)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_START_MIN)) {
 			print 'jQuery("#date_startmin").val("'.$conf->global->MAIN_DEFAULT_DATE_START_MIN.'");';
 		}
 	}
 	if (!$line->date_end) {
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_END_HOUR)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_END_HOUR)) {
 			print 'jQuery("#date_endhour").val("'.$conf->global->MAIN_DEFAULT_DATE_END_HOUR.'");';
 		}
-		if (!empty($conf->global->MAIN_DEFAULT_DATE_END_MIN)) {
+		if (isset($conf->global->MAIN_DEFAULT_DATE_END_MIN)) {
 			print 'jQuery("#date_endmin").val("'.$conf->global->MAIN_DEFAULT_DATE_END_MIN.'");';
 		}
 	}