diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 751aed5aef5..623f409103b 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -235,14 +235,14 @@ function isModEnabled($module)
 }
 
 /**
- * isDolValidTms check if a timestamp is valid.
+ * isDolTms check if a timestamp is valid.
  *
  * @param  int|string|null $timestamp timestamp to check
  * @return bool
  */
-function isDolValidTms($timestamp)
+function isDolTms($timestamp)
 {
-	if ($timestamp == '') {
+	if ($timestamp === '') {
 		dol_syslog('Using empty string for a timestamp is deprecated, prefer use of null when calling page '.$_SERVER["PHP_SELF"], LOG_NOTICE);
 		return false;
 	}
diff --git a/htdocs/projet/class/project.class.php b/htdocs/projet/class/project.class.php
index 5fc55e2da5f..5d84390383e 100644
--- a/htdocs/projet/class/project.class.php
+++ b/htdocs/projet/class/project.class.php
@@ -849,9 +849,9 @@ class Project extends CommonObject
 			$sql = "SELECT rowid FROM ".MAIN_DB_PREFIX.$tablename." WHERE ".$projectkey." IN (".$this->db->sanitize($ids).") AND entity IN (".getEntity($type).")";
 		}
 
-		if (isDolValidTms($date_start) && $type == 'loan') {
+		if (isDolTms($date_start) && $type == 'loan') {
 			$sql .= " AND (dateend > '".$this->db->idate($date_start)."' OR dateend IS NULL)";
-		} elseif (isDolValidTms($date_start) && ($type != 'project_task')) {	// For table project_taks, we want the filter on date apply on project_time_spent table
+		} elseif (isDolTms($date_start) && ($type != 'project_task')) {	// For table project_taks, we want the filter on date apply on project_time_spent table
 			if (empty($datefieldname) && !empty($this->table_element_date)) {
 				$datefieldname = $this->table_element_date;
 			}
@@ -861,9 +861,9 @@ class Project extends CommonObject
 			$sql .= " AND (".$datefieldname." >= '".$this->db->idate($date_start)."' OR ".$datefieldname." IS NULL)";
 		}
 
-		if (isDolValidTms($date_end) && $type == 'loan') {
+		if (isDolTms($date_end) && $type == 'loan') {
 			$sql .= " AND (datestart < '".$this->db->idate($date_end)."' OR datestart IS NULL)";
-		} elseif (isDolValidTms($date_end) && ($type != 'project_task')) {	// For table project_taks, we want the filter on date apply on project_time_spent table
+		} elseif (isDolTms($date_end) && ($type != 'project_task')) {	// For table project_taks, we want the filter on date apply on project_time_spent table
 			if (empty($datefieldname) && !empty($this->table_element_date)) {
 				$datefieldname = $this->table_element_date;
 			}