Warning: Date.prototype.toLocaleFormat is deprecated; consider using Intl.DateTimeFormat instead

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The non-standard Date.prototype.toLocaleFormat() method is deprecated and shouldn't be used anymore. It uses a format string in the same format expected by the strftime() function in C. The function is no longer available in Firefox 58+.

The Date.prototype.toLocaleFormat() method is deprecated and will be removed (no cross-browser support, available in Firefox only).

const today = new Date();
const date = today.toLocaleFormat("%A, %e. %B %Y");

console.log(date);
// In German locale
// "Freitag, 10. März 2017"

The ECMA-402 (ECMAScript Intl API) standard specifies standard objects and methods that enable language sensitive date and time formatting (available in Chrome 24+, Firefox 29+, IE11+, Safari10+).

You can now either use the Date.prototype.toLocaleDateString method if you just want to format one date.

const today = new Date();
const options = {
  weekday: "long",
  year: "numeric",
  month: "long",
  day: "numeric",
};
const date = today.toLocaleDateString("de-DE", options);

console.log(date);
// "Freitag, 10. März 2017"

Or, you can make use of the Intl.DateTimeFormat object, which allows you to cache an object with most of the computations done so that formatting is fast. This is useful if you have a loop of dates to format.

const options = {
  weekday: "long",
  year: "numeric",
  month: "long",
  day: "numeric",
};
const dateFormatter = new Intl.DateTimeFormat("de-DE", options);

const dates = [Date.UTC(2012, 11, 20, 3, 0, 0), Date.UTC(2014, 4, 12, 8, 0, 0)];

dates.forEach((date) => console.log(dateFormatter.format(date)));

// "Donnerstag, 20. Dezember 2012"
// "Montag, 12. Mai 2014"

The Date object offers several methods to build a custom date string.

new Date().toLocaleFormat("%Y%m%d");
// "20170310"

Can be converted to:

const now = new Date();
const date =
  now.getFullYear() * 10000 + (now.getMonth() + 1) * 100 + now.getDate();

console.log(date);
// "20170310"

• Date.prototype.toLocaleDateString
• Intl.DateTimeFormat