In shape of function, you can use this code in functions.php:

function wpog_custom_date($date){

    $new_date = getdate(strtotime($date));

    // Array that holds customized month’s name

    $my_months=[

            ‘January’   => ‘januar’,

            ‘February’  => ‘februar’,

            ‘March’     => ‘mart’,

            ‘April’     => ‘april’,

            ‘May’       => ‘maj’,

            ‘June’      => ‘jun’,

            ‘July’      => ‘jul’,

            ‘August’    => ‘avgust’,

            ‘September’ => ‘septembar’,

            ‘October’   => ‘oktobar’,

            ‘November’  => ‘novembar’,

            ‘December’  => ‘decembar’,

        ];

        $new_date[‘month’]= $my_months[$new_date[‘month’]];

return $new_date[‘mday’].’. ‘.$new_date[‘month’]. ‘ ‘. $new_date[‘year’].’.’;

    }

function wpog_change_translate_text_multiple( $translated ) {
$text = array(
‘January’ => ‘Jan11’,
‘February’ => ‘Feb22’,
‘March’ => ‘Mar33’,
);
$translated = str_ireplace( array_keys($text), $text, $translated );
return $translated;
}
add_filter( ‘gettext’, ‘wpog_change_translate_text_multiple’, 20 );