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() 不携带参数时，其默认区域和时区取决于实现
console.log(date.toLocaleDateString());
// "2012/12/12" 如果在 zh-CN 区域以及东八区（北京时间）下运行

function toLocaleDateStringSupportsLocales() {
  try {
    new Date().toLocaleDateString("i");
  } catch (e) {
    return e.name === "RangeError";
  }
  return false;
}

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

// 以下格式化输出均假设使用区域的本地时区；
// 对于美国，为 America/Los_Angeles

// 美式英语，使用 month-day-year 的顺序
console.log(date.toLocaleDateString("en-US"));
// "12/20/2012"

// 英式英语，使用 day-month-year 的顺序
console.log(date.toLocaleDateString("en-GB"));
// "20/12/2012"

// 韩国，使用 year-month-day 的顺序
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"));
// "Û±Û³Û¹Û±/Û¹/Û³Û°"

// 大多数阿拉伯国家使用真正的阿拉伯数字
console.log(date.toLocaleDateString("ar-EG"));
// "٢٠‏/١٢‏/٢٠١٢"

// 对于日语，应用倾向于使用日本的和历，
// 2012 年是平成时代的第 24 年
console.log(date.toLocaleDateString("ja-JP-u-ca-japanese"));
// "24/12/20"

// 当使用的语言不被支持，例如
// 巴厘岛语，则可以包含一种回退语言，这里以印尼语为例
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"

// 应用程序可能想要使用 UTC 时间，并使其可见
options.timeZone = "UTC";
options.timeZoneName = "short";
console.log(date.toLocaleDateString("en-US", options));
// "Thursday, December 20, 2012, UTC"