JavaScript Dates
toLocaleDateStringformats a date the way a reader in a given place expects.
Never build a date string by joining the parts yourself.
The rules differ by country and the built-in formatters know them.
Example
javascript
const date = new Date(Date.UTC(2026, 0, 15));
console.log(date.toLocaleDateString("en-GB", { timeZone: "UTC" }));The output is 15/01/2026, the British order.
toLocaleDateString formats the date part.
toLocaleTimeString formats the time part.
toISOString gives the machine-readable form.
Syntax
javascript
date.toLocaleDateString(locale, options);Pass a timeZone option for a predictable result.
The same moment reads differently around the world.
Example
javascript
const date = new Date(Date.UTC(2026, 0, 15));
const options = { timeZone: "UTC" };
console.log(date.toLocaleDateString("en-GB", options));
console.log(date.toLocaleDateString("en-US", options));Britain puts the day first; the United States puts the month first.
Options control how much of each part is shown.
Example
javascript
const date = new Date(Date.UTC(2026, 0, 15));
console.log(date.toLocaleDateString("en-GB", {
timeZone: "UTC",
day: "numeric",
month: "long",
year: "numeric"
}));The output is 15 January 2026.
weekday adds the day name.
Example
javascript
const date = new Date(Date.UTC(2026, 0, 15));
console.log(date.toLocaleDateString("en-GB", {
timeZone: "UTC",
weekday: "long",
day: "numeric",
month: "long"
}));The names come from the locale, so they translate automatically.
toISOString is for storing and sending, not for showing.
It is always UTC and always the same shape.
Example
javascript
const date = new Date(Date.UTC(2026, 0, 15));
console.log(date.toISOString());
console.log(date.toISOString().slice(0, 10));Slicing the first ten characters gives just the date.
Intl.DateTimeFormat is faster when formatting many dates.
Example
javascript
const formatter = new Intl.DateTimeFormat("en-GB", { timeZone: "UTC" });
console.log(formatter.format(new Date(Date.UTC(2026, 0, 15))));
console.log(formatter.format(new Date(Date.UTC(2026, 5, 1))));Build it once and reuse it for the whole list.
Complete Example
html
<!DOCTYPE html>
<html>
<head>
<title>JavaScript Date Formatting</title>
</head>
<body>
<h1>Date Formatting</h1>
<p id="out"></p>
<script>
const date = new Date(Date.UTC(2026, 0, 15));
const options = { timeZone: "UTC" };
document.getElementById("out").innerHTML =
"British: " + date.toLocaleDateString("en-GB", options) +
"<br>American: " + date.toLocaleDateString("en-US", options) +
"<br>Long: " + date.toLocaleDateString("en-GB", {
timeZone: "UTC", day: "numeric", month: "long", year: "numeric"
}) +
"<br>ISO: " + date.toISOString().slice(0, 10);
</script>
</body>
</html>Run the above example in the Try It Editor.
Try a short month:
Change month: "long" to "short".
toLocaleDateString formats for a human reader.toISOString is for storage, not display.Intl.DateTimeFormat is faster when reused.Building date strings by hand gets the order wrong for most of the world.
The locale formatters already know every one of those rules.
Use ISO for machines and locale formatting for people.