Date.prototype.toLocaleDateString()

const event = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));
const options = {
  weekday: "long",
  year: "numeric",
  month: "long",
  day: "numeric",
};

console.log(event.toLocaleDateString("de-DE", options));
// Expected output (varies according to local timezone): Donnerstag, 20. Dezember 2012

console.log(event.toLocaleDateString("ar-EG", options));
// Expected output (varies according to local timezone): الخميس، ٢٠ ديسمبر، ٢٠١٢

console.log(event.toLocaleDateString(undefined, options));
// Expected output (varies according to local timezone and default locale): Thursday, December 20, 2012

toLocaleDateString()
toLocaleDateString(locales)
toLocaleDateString(locales, options)

const date = new Date(Date.UTC(2012, 11, 12, 3, 0, 0));

// toLocaleDateString() without arguments depends on the implementation,
// the default locale, and the default time zone
console.log(date.toLocaleDateString());
// "12/11/2012" if run in en-US locale with time zone America/Los_Angeles

function toLocaleDateStringSupportsLocales() {
  return (
    typeof Intl === "object" &&
    !!Intl &&
    typeof Intl.DateTimeFormat === "function"
  );
}

const date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

// formats below assume the local time zone of the locale;
// America/Los_Angeles for the US

// US English uses month-day-year order
console.log(date.toLocaleDateString("en-US"));
// "12/20/2012"

// British English uses day-month-year order
console.log(date.toLocaleDateString("en-GB"));
// "20/12/2012"

// Korean uses year-month-day order
console.log(date.toLocaleDateString("ko-KR"));
// "2012. 12. 20."

// Event for Persian, It's hard to manually convert date to Solar Hijri
console.log(date.toLocaleDateString("fa-IR"));
// "۱۳۹۱/۹/۳۰"

// Arabic in most Arabic speaking countries uses real Arabic digits
console.log(date.toLocaleDateString("ar-EG"));
// "٢٠‏/١٢‏/٢٠١٢"

// for Japanese, applications may want to use the Japanese calendar,
// where 2012 was the year 24 of the Heisei era
console.log(date.toLocaleDateString("ja-JP-u-ca-japanese"));
// "24/12/20"

// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
console.log(date.toLocaleDateString(["ban", "id"]));
// "20/12/2012"

const date = new Date(Date.UTC(2012, 11, 20, 3, 0, 0));

// Request a weekday along with a long date
const options = {
  weekday: "long",
  year: "numeric",
  month: "long",
  day: "numeric",
};
console.log(date.toLocaleDateString("de-DE", options));
// "Donnerstag, 20. Dezember 2012"

// An application may want to use UTC and make that visible
options.timeZone = "UTC";
options.timeZoneName = "short";
console.log(date.toLocaleDateString("en-US", options));
// "Thursday, December 20, 2012, UTC"