diff --git a/htdocs/core/lib/date.lib.php b/htdocs/core/lib/date.lib.php
index 2d5bf7ab0cd..4b9401498d7 100644
--- a/htdocs/core/lib/date.lib.php
+++ b/htdocs/core/lib/date.lib.php
@@ -766,7 +766,7 @@ function num_between_day($timestampStart, $timestampEnd, $lastday=0)
  *	@param     	int			$inhour             0: return number of days, 1: return number of hours
  *	@param		int			$lastday            We include last day, 0: no, 1:yes
  *  @param		int			$halfday			Tag to define half day when holiday start and end
- *  @param      string		$countrycode        Country code (company country code if not defined)
+ *  @param      string		$country_code       Country code (company country code if not defined)
  *	@return    	int								Number of days or hours
  */
 function num_open_day($timestampStart, $timestampEnd, $inhour=0, $lastday=0, $halfday=0, $country_code='')