Conversion of Italian calendar for react-multi-date-picker library

I have used react-multi-date-picker for my project and I am using multiple mode. For this I have to use Italian calendar when my language is Italian. I was tried with locale="it" but it is not working. After research, I got one solution which is, create js file which contain Italian months, weekdays numbers and meridiems. Also I had given reference for react-date-object. In that various types of the locale js files created. created same and tried to pass it to DatePicker but it showing me wrong output.
Actually, calendar is converting well but date is set to wrong days.

Here is the my App.js file for DatePicker

<!-- begin snippet: js hide: false console: true babel: false -->

<!-- language: lang-js -->

import DatePicker from "react-multi-date-picker";
import DatePanel from "react-multi-date-picker/plugins/date_panel";
import italian_it from './italianCalendar';
function App() {
  return (
    <div className="App">
      <header className="App-header">
        <DatePicker
          locale={italian_it}
          multiple
          format="DD/MM/YYYY"
          plugins={[<DatePanel />]}
        />
      </header>
    </div>
  );
}

export default App;

My italianCalendar file is as below,

module.exports = { name: "italian_it", months: [ ["gennaio", "gennaio"], ["febbraio", "febbraio"], ["marzo", "marzo"], ["aprile", "aprile"], ["maggio", "maggio"], ["giugno", "giugno"], ["luglio", "luglio"], ["agosto", "agosto"], ["settembre", "settembre"], ["ottobre", "ottobre"], ["novembre", "novembre"], ["dicembre", "dicembre"], ], weekDays: [ ["domenica", "dom"], ["lunedì", "lun"], ["martedì", "mar"], ["mercoledì", "mer"], ["giovedì", "gio"], ["venerdì", "ven"], ["sabato", "sab"]], digits: ["0", "1", "2", "3", "4", "5", "6", "7", "8", "9"], meridiems: [ ["am", "am"], ["pm", "pm"], ], };

<!-- end snippet -->

Output is showing like this.

For reference, I have added my code over sandbox

https://codesandbox.io/s/keen-worker-mnvdno

You could use the react-date-object library. It provides a DateObject class which can handle different kind of calendars, try this :

import React from "react";
import ReactDOM from "react-dom";
import DatePicker from "react-multi-date-picker";
import DatePanel from "react-multi-date-picker/plugins/date_panel";
import { DateObject } from "react-date-object";

// Create a new DateObject with the Italian calendar
const italianDateObject = new DateObject({ calendar: "italian" });

function App() {
  // Set the default calendar to the Italian calendar
  const defaultCalendar = italianDateObject.calendar;

  return (
    <div className="App">
      <header className="App-header">
        <DatePicker
          defaultCalendar={defaultCalendar}
          multiple
          format="DD/MM/YYYY"
          plugins={[<DatePanel />]}
        />
      </header>
    </div>
  );
}

ReactDOM.render(<App />, document.getElementById("root"));