diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 389519d7b7f..6ff7522b68d 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -4687,7 +4687,7 @@ class Form
 	 *
 	 *	@param	timestamp	$set_time 		Pre-selected date (must be a local PHP server timestamp), -1 to keep date not preselected, '' to use current date (emptydate must be 0).
 	 *	@param	string		$prefix			Prefix for fields name
-	 *	@param	int			$h				1=Show also hours
+	 *	@param	int			$h				1=Show also hours (-1 has same effect, but hour and minutes are prefilled with 23:59 if $set_time = -1)
 	 *	@param	int			$m				1=Show also minutes
 	 *	@param	int			$empty			0=Fields required, 1=Empty inputs are allowed, 2=Empty inputs are allowed for hours only
 	 *	@param	string		$form_name 		Not used
@@ -4751,9 +4751,9 @@ class Form
 			$syear = '';
 			$smonth = '';
 			$sday = '';
-			$shour = !isset($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;
-			$ssec = !isset($conf->global->MAIN_DEFAULT_DATE_SEC) ? '' : $conf->global->MAIN_DEFAULT_DATE_SEC;
+			$shour = !isset($conf->global->MAIN_DEFAULT_DATE_HOUR) ? ($h == -1 ? '23' : '') : $conf->global->MAIN_DEFAULT_DATE_HOUR;
+			$smin = !isset($conf->global->MAIN_DEFAULT_DATE_MIN) ? ($h == -1 ? '59' : '') : $conf->global->MAIN_DEFAULT_DATE_MIN;
+			$ssec = !isset($conf->global->MAIN_DEFAULT_DATE_SEC) ? ($h == -1 ? '59' : '') : $conf->global->MAIN_DEFAULT_DATE_SEC;
 		}
 
 		// You can set MAIN_POPUP_CALENDAR to 'eldy' or 'jquery'
diff --git a/htdocs/projet/tasks.php b/htdocs/projet/tasks.php
index 12da09053cd..385b63142d4 100644
--- a/htdocs/projet/tasks.php
+++ b/htdocs/projet/tasks.php
@@ -393,7 +393,7 @@ if ($action == 'create' && $user->rights->projet->creer && (empty($object->third
 
 	// Date end
 	print '<tr><td>'.$langs->trans("DateEnd").'</td><td>';
-	print $form->select_date(($date_end?$date_end:-1),'datee',1,1,0,'',1,1,1);
+	print $form->select_date(($date_end?$date_end:-1),'datee',-1,1,0,'',1,1,1);
 	print '</td></tr>';
 
 	// Planned workload