Temporal.ZonedDateTime.prototype.toString()

options Optional

An object containing the following property:

calendarName Optional

Whether to show the calendar annotation ([u-ca=calendar_id]) in the return value. Possible values are:

"auto" (default)

Include the calendar annotation if the calendar is not "iso8601".

"always"

Always include the calendar annotation.

"never"

Never include the calendar annotation. This makes the returned string not recoverable to the same Temporal.ZonedDateTime instance, although the date value still remains the same.

"critical"

Always include the calendar annotation, and add a critical flag: [!u-ca=calendar_id]. Useful when sending the string to certain systems, but not useful for Temporal itself.

fractionalSecondDigits Optional

Either an integer from 0 to 9, or the string "auto". The default is "auto". If "auto", then trailing zeros are removed from the fractional seconds. Otherwise, the fractional part of the second component contains this many digits, padded with zeros or rounded as necessary.

roundingMode Optional

A string specifying how to round off fractional second digits beyond fractionalSecondDigits. See Intl.NumberFormat(). Defaults to "trunc".

smallestUnit Optional

A string specifying the smallest unit to include in the output. Possible values are "minute", "second", "millisecond", "microsecond", and "nanosecond", or their plural forms, which (except "minute") are equivalent to fractionalSecondDigits values of 0, 3, 6, 9, respectively. If specified, then fractionalSecondDigits is ignored.

timeZoneName Optional

Whether to show the time zone name ([time_zone_id]) in the return value. Possible values are:

"auto" (default)

Always include the time zone name.

"never"

Never include the time zone name. This makes the returned string not recoverable to the same Temporal.ZonedDateTime instance.

"critical"

Always include the time zone name, and add a critical flag: [!time)zone_id]. Useful when sending the string to certain systems, but not useful for Temporal itself.

offset Optional

Whether to show the offset (±HH:mm) in the return value. Possible values are:

"auto" (default)

Always include the offset.

"never"

Never include the offset. This makes the returned string not recoverable to the same Temporal.ZonedDateTime instance, if the time zone is included but the time is ambiguous, or if the time zone is also not included.

A string in the RFC 9557 format representing this date-time. The offset and calendar/time zone annotations are included as specified.

RangeError

Thrown if any of the options is invalid.

TypeError

Thrown if options is not an object or undefined.

const zdt = Temporal.ZonedDateTime.from(
  "2021-08-01T12:34:56[America/New_York]",
);
console.log(zdt.toString()); // '2021-08-01T12:34:56-04:00[America/New_York]'

Even for the UTC time zone, the offset is +00:00, not Z:

const zdt = Temporal.ZonedDateTime.from("2021-08-01T12:34:56[UTC]");
console.log(zdt.toString()); // '2021-08-01T12:34:56+00:00[UTC]'

For examples with rounding times, see Temporal.PlainTime.prototype.toString(). For examples with displaying calendars, see Temporal.PlainDate.prototype.toString(). Here we show controlling the display of time zone and offset:

const zdt = Temporal.ZonedDateTime.from(
  "2021-08-01T12:34:56[America/New_York]",
);
console.log(zdt.toString({ timeZoneName: "auto", offset: "never" })); // '2021-08-01T12:34:56[America/New_York]'
console.log(zdt.toString({ timeZoneName: "never", offset: "auto" })); // '2021-08-01T12:34:56-04:00'
console.log(zdt.toString({ timeZoneName: "never", offset: "never" })); // '2021-08-01T12:34:56'
console.log(zdt.toString({ timeZoneName: "critical", offset: "never" })); // '2021-08-01T12:34:56[!America/New_York]'

• Temporal.ZonedDateTime
• Temporal.ZonedDateTime.from()
• Temporal.ZonedDateTime.prototype.toJSON()
• Temporal.ZonedDateTime.prototype.toLocaleString()