Temporal Formats

Temporal dates can be serialized as strings in different ways:

PlainDate toString()

The toString() method returns a standard ISO string.

Example

const date = Temporal.PlainDate.from("2026-05-17");

let text = date.toString();

PlainTime toString()

A PlainTime value is formatted as a time string.

Example

const time = Temporal.PlainTime.from("14:30:15");

let text = time.toString();

PlainDateTime toString()

A PlainDateTime value includes both date and time.

Example

const dateTime = Temporal.PlainDateTime.from("2026-05-17T14:30:15");

let text = dateTime.toString();

ZonedDateTime toString()

A ZonedDateTime string includes the offset and time zone.

Example

const zoned = Temporal.ZonedDateTime.from("2026-05-17T14:30:15[Europe/Oslo]");

let text = zoned.toString();

Remove Smaller Time Units

You can control how much detail to include.

For example, you can hide seconds or milliseconds.

Example

const time = Temporal.PlainTime.from("14:30:15.123");

let text = time.toString({ smallestUnit: "minute" });

Control Fractional Digits

You can choose how many decimal digits to include.

Example

const time = Temporal.PlainTime.from("14:30:15.123456789");

let text = time.toString({ fractionalSecondDigits: 3 });

PlainDate toLocaleString()

Use toLocaleString() to format a value using the user's locale.

Example

const date = Temporal.PlainDate.from("2026-05-17");

let text_us = date.toLocaleString("en-US");

let text_de = date.toLocaleString("de-DE");

The output depends on the chosen locale.

ZonedDateTime toLocaleString()

Example

const zoned = Temporal.ZonedDateTime.from("2026-05-17T14:30:15+01:00[Europe/Oslo]");

let text = zoned.toLocaleString("en-US", {

  dateStyle: "full",

  timeStyle: "short"

});

Format with Intl.DateTimeFormat

Use Intl.DateTimeFormat when you need more control over the output.

Example

const date = Temporal.PlainDate.from("2026-05-17");

const formatter = new Intl.DateTimeFormat("en-US", {

  year: "numeric",

  month: "long",

  day: "numeric"

});

let text = formatter.format(date);

Format Date and Time Together

You can format a PlainDateTime with both date and time options.

Example

const dateTime = Temporal.PlainDateTime.from("2026-05-17T14:30:15");

const formatter = new Intl.DateTimeFormat("en-GB", {

  year: "numeric",

  month: "short",

  day: "numeric",

  hour: "2-digit",

  minute: "2-digit"

});

let text = formatter.format(dateTime);

ZonedDateTime toLocaleString()

The Intl.DateTimeFormat() method does not accept a Temporal.ZonedDateTime object as input.

This design choice prevents conflicts between the time zone held by the ZonedDateTime and the time zone defined in the formatter.

The best solution is to use toLocaleString() instead.

Example

const zoned = Temporal.ZonedDateTime.from("2026-05-17T14:30:15+01:00[Europe/Oslo]");

let text = zoned.toLocaleString("en-US", {

  dateStyle: "full",

  timeStyle: "short"

});

When to Use Each Method

• Use toString() for standard ISO output.
• Use toLocaleString() for simple local formatting.
• Use Intl.DateTimeFormat for custom formatting.