[PHP] Difference betwen tow date

    public function _getDiffInHours( $date ){

        $usDate = str_replace ( "/" , "-" ,$date);

        $now = strtotime("now");

        $nextDate = strtotime ( $usDate );

        if(! is_numeric( $nextDate ) || ! is_numeric( $now ) || $nextDate <  $now ){

            return 0;

        }

        return floor( ($nextDate-$now) / (60*60));

    }

Log in other file that system.log

    public function _log($msg){
        $nameFile = 'other-file-'.date ( "Y-m-d-H" ).'.log';
        Mage::log($msg, null, $nameFile );
    }

Replace accented characters

    public function normaliza ($string){
        $a = 'ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõöøùúûýýþÿŔŕ';   
        $b = 'aaaaaaaceeeeiiiidnoooooouuuuybsaaaaaaaceeeeiiiidnoooooouuuyybyRr';
        $string = utf8_decode($string);   
        $string = strtr($string, utf8_decode($a), $b);
        $string = strtolower($string);
        return  utf8_encode($string) ;
    }