diff --git a/htdocs/core/lib/date.lib.php b/htdocs/core/lib/date.lib.php
index ac44d6e5975..b06baaa9288 100644
--- a/htdocs/core/lib/date.lib.php
+++ b/htdocs/core/lib/date.lib.php
@@ -542,6 +542,7 @@ function dol_get_first_day_week($day,$month,$year,$gm=false)
  *  @param      string		$countrycode        Country code
  *	@param      int			$lastday            Last day is included, 0: no, 1:yes
  *	@return   	int								Nombre de jours feries
+ *  @see num_between_day, num_open_day
  */
 function num_public_holiday($timestampStart, $timestampEnd, $countrycode='FR', $lastday=0)
 {
@@ -722,6 +723,7 @@ function num_public_holiday($timestampStart, $timestampEnd, $countrycode='FR', $
  *	@param	   int			$timestampEnd       Timestamp end UTC
  *	@param     int			$lastday            Last day is included, 0: no, 1:yes
  *	@return    int								Number of days
+ *  @see also num_public_holiday, num_open_day
  */
 function num_between_day($timestampStart, $timestampEnd, $lastday=0)
 {
@@ -751,6 +753,7 @@ function num_between_day($timestampStart, $timestampEnd, $lastday=0)
  *  @param		int			$halfday			Tag to define half day when holiday start and end
  *  @param      string		$country_code       Country code (company country code if not defined)
  *	@return    	int								Number of days or hours
+ *  @see also num_between_day, num_public_holiday
  */
 function num_open_day($timestampStart, $timestampEnd, $inhour=0, $lastday=0, $halfday=0, $country_code='')
 {
diff --git a/test/phpunit/DateLibTest.php b/test/phpunit/DateLibTest.php
index 5f33a9f5095..02d85164d79 100644
--- a/test/phpunit/DateLibTest.php
+++ b/test/phpunit/DateLibTest.php
@@ -167,7 +167,82 @@ class DateLibTest extends PHPUnit_Framework_TestCase
 		return $result;
     }
 
-
+    /**
+     * testNumPublicHoliday
+     *
+     * @return	void
+     */
+    public function testNumPublicHoliday()
+    {
+        global $conf,$user,$langs,$db;
+        $conf=$this->savconf;
+        $user=$this->savuser;
+        $langs=$this->savlangs;
+        $db=$this->savdb;
+    
+        // With same hours - Tuesday/Wednesday jan 2013
+        $date1=dol_mktime(0, 0, 0, 1, 1, 2013);
+        $date2=dol_mktime(0, 0, 0, 1, 2, 2013);
+    
+        $result=num_public_holiday($date1,$date2,'FR',1);
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(1,$result,'NumPublicHoliday for Tuesday/Wednesday jan 2013 for FR');   // 1 closed days
+    
+        $result=num_public_holiday($date1,$date2,'XX',1);
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(0,$result,'NumPublicHoliday for Tuesday/Wednesday jan 2013 for XX');   // no closed days (country unknown)
+        
+        // With same hours - Friday/Sunday jan 2013
+        $date1=dol_mktime(0, 0, 0, 1, 4, 2013);
+        $date2=dol_mktime(0, 0, 0, 1, 6, 2013);
+        
+        $result=num_public_holiday($date1,$date2,'FR',1);
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(2,$result,'NumPublicHoliday for FR');   // 1 opened day, 2 closed days 
+        
+        $result=num_public_holiday($date1,$date2,'XX',1);
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(2,$result,'NumPublicHoliday for XX');   // 1 opened day, 2 closed days (even if country unknown)
+    }
+    
+    /**
+     * testNumOpenDay
+     *
+     * @return	void
+     */
+    public function testNumOpenDay()
+    {
+        global $conf,$user,$langs,$db;
+        $conf=$this->savconf;
+        $user=$this->savuser;
+        $langs=$this->savlangs;
+        $db=$this->savdb;
+        
+        // With same hours - Tuesday/Wednesday jan 2013
+        $date1=dol_mktime(0, 0, 0, 1, 1, 2013);
+        $date2=dol_mktime(0, 0, 0, 1, 2, 2013);
+        
+        $result=num_open_day($date1,$date2,0,1,0,'FR');
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(1,$result,'NumOpenDay Tuesday/Wednesday jan 2013 for FR');   // 1 opened days
+        
+        $result=num_open_day($date1,$date2,0,1,0,'XX');
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(2,$result,'NumOpenDay Tuesday/Wednesday jan 2013 for XX');   // 2 opened days (country unknown)
+        
+        // With same hours - Friday/Sunday jan 2013
+        $date1=dol_mktime(0, 0, 0, 1, 4, 2013);
+        $date2=dol_mktime(0, 0, 0, 1, 6, 2013);
+        
+        $result=num_open_day($date1,$date2,0,1,0,'FR');
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(1,$result,'NumOpenDay for FR');   // 1 opened day, 2 closed
+        
+        $result=num_open_day($date1,$date2,'XX',1);
+        print __METHOD__." result=".$result."\n";
+        $this->assertEquals(1,$result,'NumOpenDay for XX');   // 1 opened day, 2 closes (even if country unknown)
+    }
+    
     /**
      * testConvertTime2Seconds
      *