Convert date and digit into bengali in wordpress

if(function_exists('number_format_i18n')){
    if(is_admin()){return;}

    add_filter('number_format_i18n', 'wpbanglatools_i18n_digit', 10, 1);
    //add_filter('date_i18n', 'wpbanglatools_i18n_date',10,2);  //enable this line if need to make the date bengali.
}

function wpbanglatools_i18n_digit($en_number){
    $en_digits = array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9');
    $bn_digits = array('০', '১', '২', '৩', '৪', '৫', '৬', '৭', '৮', '৯');
    $en_number = str_replace($en_digits, $bn_digits, $en_number);
    //var_dump($en_number);
    return $en_number;
}

function wpbanglatools_i18n_date($en_date, $format){
    //var_dump($format);
    //check format in wp codex http://codex.wordpress.org/Formatting_Date_and_Time
    //month
    $en_months = array('January','February','March','April','May','June','July','August','September','October','November','December');
    $bn_months = array('জানুয়ারী','ফেব্রুয়ারী','মার্চ','এপ্রিল','মে','জুন','জুলাই','আগস্ট','সেপ্টেম্বর','অক্টোবর','নভেম্ভর','ডিসেম্বর');

    $en_months_short = array('January','February','March','April','May','June','July','August','September','October','November','December');
    $bn_months_short = array('জানুয়ারী','ফেব্রুয়ারী','মার্চ','এপ্রিল','মে','জুন','জুলাই','আগস্ট','সেপ্টেম্বর','অক্টোবর','নভেম্ভর','ডিসেম্বর');

    //week
    $en_weeks=  array('Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday');
    $en_weeks_short=  array('Sun','Mon','Tue','Wed','Thu','Fri','Sat');
    $en_weeks_short_initial=  array('S','M','T','W','T','F','S');

    $bn_weeks = array ('রবিবার','সোমবার','মঙ্গলবার','বুধবার','বৃহঃবার','শুক্রবার','শনিবার');
    $bn_weeks_short = array ('রবি','সোম','মঙ্গল','বুধ','বৃহঃ','শুক্র','শনি');
    $bn_weeks_short_initial=  array('র','সো','ম','বু','বৃ','শু','শ');

    //meriian ...
    $en_meridian = array('am','pm');
    $bn_meridian = array('পুর্বাহ্ন','অপরাহ্ণ');

    //ordinal
    $en_ordinal = array('st','nd','rd','th');
    $bn_ordinal = array('','','','','');
    //let's apply regex depending on format
    //parse english month with data format
    //details about dataformat used in wordpress is here http://codex.wordpress.org/Formatting_Date_and_Time
    if(strpos($format,'F') !== FALSE)
    {
        //F     Textual full    January – December
        $en_date = str_replace($en_months, $bn_months, $en_date);
    }
    if(strpos($format,'M'))
    {
        //M     Textual three letters   Jan - Dec
        $en_date = str_replace($en_months_short, $bn_months_short, $en_date);
    }

    //now parse weekday depending on data format
    if(strpos($format,'l'))
    {
        //l     Full name  (lowercase 'L')  Sunday – Saturday
        $en_date = str_replace($en_weeks, $bn_weeks, $en_date);
    }
    if(strpos($format,'D'))
    {
        //D     Three letter name   Mon – Sun
        $en_date = str_replace($en_weeks_short, $bn_weeks_short, $en_date);

    }
    if(strpos($format,'a') || strpos($format,'A'))
    {
        //a     Lowercase   am, pm
        //A     Uppercase   AM, PM
        $en_date = str_ireplace($en_meridian, $bn_meridian, $en_date); // why not run a case insensitive regex :P

    }
    if(strpos($format,'j') && strpos($format,'S'))
    {
        $en_date = str_ireplace($en_ordinal, $bn_ordinal, $en_date);
    }
    //at last make the digits bangla :D
    //though we need to make digit banglafy for date if $format contains d,j,m,n,Y,y,
    return wpbanglatools_i18n_digit($en_date);
}