JavaScript Date toISOString() Method

Last Updated : 11 Jul, 2025

The date.toISOString() method is used to convert the given data object’s contents into a string in ISO format (ISO 8601) i.e. in the form of (YYYY-MM-DDTHH:mm:ss.sssZ or ±YYYYYY-MM-DDTHH:mm:ss.sssZ). The date object is created using the date() constructor.

Output

1996-10-15T05:35:32.000Z

Syntax

dateObj.toISOString()

Parameters

This method does not take any parameters. It is just used along with a Date object created using the Date() constructor.

Return Values

It returns the converted string of Date() constructor contents into ISO format (ISO 8601).

Note: The DateObj is a valid Date object created using the Date()constructor.

Example 1: Here nothing as a parameter is passed while creating a date object but still toISOString() method returns the current day name, month name, date, year, and time.

Output:

2018-04-23T10:26:00.996Z

Example 2: Here we will pass a date object toISOString() method to return the day name, month name, date, year, and time.

Output:

1996-10-13T08:35:32.000Z

Note: Months, Dates, hours, minutes, seconds, and milliseconds should all be in their respective range of 0 to 11, 1 to 31, 0 to 23, 0 to 59, 0 to 59, 0 to 999 respectively.