1 => string 'id_1=61' (length=7)
			2 => string 'id_2=62' (length=7)
	$arrayBase will have :
		array (size=3)
			0 => string 'id_0=' (length=5)
			1 => string 'id_1=' (length=5)
			2 => string 'id_2=' (length=5)
	Then agendasId array will contain only agendasId 
		array (size=3)
			0 => string '60' (length=2)
			1 => string '61' (length=2)
			2 => string '62' (length=2)
*/
$arrayBase = generateArrayIdNum(count($idPart));
$agendasId = array();
for ($i = 0; $i < count($idPart); $i++) {
    $agendasId[] = str_replace($arrayBase[$i], '', $idPart[$i]);
}
//get date
$date = htmlspecialchars($_GET['date']);
$infos = $agendaManager->getAllActivitiesByDate($agendasId, $date);
$gView->dayCalendar($infos, $idUser);
//Generate an array because we want to do diff with the other
function generateArrayIdNum($length)
{
    $arrayNum = array();
    for ($i = 0; $i < $length; $i++) {
        $arrayNum[] = "id_{$i}=";
    }
    return $arrayNum;
}