Javascript date parsing from string

Date.parse()

The Date.parse() static method parses a string representation of a date, and returns the date’s timestamp.

Only the date time string format is explicitly specified to be supported. Other formats are implementation-defined and may not work across all browsers. A library can help if many different formats are to be accommodated.

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Syntax

Parameters

A string in the date time string format. See the linked reference for caveats on using different formats.

Return value

A number representing the timestamp of the given date. If dateString fails to be parsed as a valid date, NaN is returned.

Description

This function is useful for setting date values based on string values, for example in conjunction with the setTime() method.

Because parse() is a static method of Date , you always use it as Date.parse() , rather than as a method of a Date object you created.

Examples

Using Date.parse()

The following calls all return 1546300800000 . The first will imply UTC time because it’s date-only, and the others explicitly specify the UTC timezone.

.parse("2019-01-01"); Date.parse("2019-01-01T00:00:00.000Z"); Date.parse("2019-01-01T00:00:00.000+00:00"); 

The following call, which does not specify a time zone will be set to 2019-01-01 at 00:00:00 in the local timezone of the system, because it has both date and time.

Non-standard date strings

Note: This section contains implementation-specific behavior that can be inconsistent across implementations.

Implementations usually default to the local time zone when the date string is non-standard. For consistency, we will assume that the code uses the UTC timezone.

.parse("Jan 1, 1970"); // 0 in all implementations Date.parse("Thu, 01 Jan 1970 00:00:00"); // 0 in all implementations Date.parse("1970,1,1"); // 0 in Chrome and Firefox, NaN in Safari Date.parse("02 01 1970"); // 2678400000 in Chrome and Firefox (Sun Feb 01 1970 00:00:00 GMT+0000); // NaN in Safari // With explicit timezone Date.parse("Thu, 01 Jan 1970 00:00:00 GMT+0300"); // -10800000 in all implementations in all timezones // Single number Date.parse("0"); // 946684800000 in Chrome (Sat Jan 01 2000 00:00:00 GMT+0000); // NaN in Firefox; // -62167219200000 in Safari (Sat Jan 01 0000 00:00:00 GMT+0000) // Two-digit number that may be a month Date.parse("28"); // NaN in all implementations // Two-digit year Date.parse("70/01/01"); // 0 in all implementations // Out-of-bounds date components Date.parse("2014-25-23"); // NaN in all implementations Date.parse("Mar 32, 2014"); // NaN in all implementations Date.parse("2014/25/23"); // NaN in all implementations Date.parse("2014-02-30"); // NaN in Safari and Firefox; // 1393718400000 in Chrome (Sun Mar 02 2014 00:00:00 GMT+0000) Date.parse("02/30/2014"); // 1393718400000 in all implementations 

Specifications

Browser compatibility

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Javascript date parsing from string

Last updated: Jan 13, 2023
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# Convert a String to a Date object in JavaScript

Use the Date() constructor to convert a string to a Date object.

The Date() constructor takes a valid date string as a parameter and returns a Date object.

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const str = '2022-09-24'; const date = new Date(str); console.log(date); // 👉️ 2022-09-24T00:00:00.000Z console.log(date.toDateString()); // 👉️ Sat Sep 24 2022 

We used the Date() constructor to convert a string to a Date object.

# Dealing with Invalid Dates

If you get an invalid Date when creating the Date object, you need to format the string correctly before passing it to the Date() constructor.

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const date1 = new Date('abc'); console.log(date1); // 👉️ Invalid Date const date2 = new Date('2023-12-45'); console.log(date2); // 👉️ Invalid Date 

If you have difficulties creating a valid Date object, you can pass 2 types of arguments to the Date() constructor:

1. a valid ISO 8601 string, formatted as YYYY-MM-DDTHH:mm:ss.sssZ , or just YYYY-MM-DD , if you only have a date without time.
2. multiple, comma-separated arguments that represent the year , month (0 = January to 11 = December), day of the month , hours , minutes and seconds .

# Splitting a Date string to create a valid Date

Here is an example that splits an MM/DD/YYYY formatted string (could be any other format) and passes the values as arguments to the Date() constructor to create a Date object.

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// 👇️ (MM/DD/YYYY) const str = '09/24/2022'; const [month, day, year] = str.split('/'); console.log(month); // 👉️ 09 console.log(day); // 👉️ 24 console.log(year); // 👉️ 2022 const date = new Date(+year, +month - 1, +day); console.log(date); // 👉️ Sat Sep 24 2022 

We split the date on each forward slash to get the values of the month, day and year.

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const str = '09/24/2022'; // 👇️ [ '09', '24', '2022' ] console.log(str.split('/')); 

Notice that we subtracted 1 from the month when passing it to the Date() constructor.

This is necessary because the Date constructor expects a zero-based value for the month, where January = 0, February = 1, March = 2, etc.

# Splitting a Date and Time string to create a valid Date

Here is another example, which creates a Date that also contains the hours, minutes and seconds.

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const str = '09/24/2022 07:30:14'; const [dateValues, timeValues] = str.split(' '); console.log(dateValues); // 👉️ "09/24/2022" console.log(timeValues); // 👉️ "07:30:14" const [month, day, year] = dateValues.split('/'); const [hours, minutes, seconds] = timeValues.split(':'); const date = new Date( +year, +month - 1, +day, +hours, +minutes, +seconds, ); // 👇️️ Sat Sep 24 2022 07:30:14 console.log(date); 

We first split the date and time string on the space, so we can get the date and time components as separate strings.

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const str = '09/24/2022 07:30:14'; const [dateValues, timeValues] = str.split(' '); console.log(dateValues); // 👉️ "09/24/2022" console.log(timeValues); // 👉️ "07:30:14" 

We then had to split the date string on each forward slash to get the value for the month, day and year.

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const dateValues = '09/24/2022'; console.log(dateValues.split('/')); // 👉️ [ '09', '24', '2022' ] 

Note that your separator might be different, e.g. a hyphen, but the approach is the same.

We also split the time string on each colon and assigned the hours, minutes and seconds to variables.

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const timeValues = '07:30:14'; console.log(timeValues.split(':')); // 👉️ [ '07', '30', '14' ] 

We then passed all of the values to the Date() constructor to create a Date object.

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const date = new Date(+year, +month - 1, +day, +hours, +minutes, +seconds); 

If you need to store a date string in your database, it’s best to store the ISO 8601 representation of the date.

# Getting an ISO-formatted date

You can get the ISO formatted date by calling the toISOString() method.

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const str = '09/24/2022 07:30:14'; const [dateValues, timeValues] = str.split(' '); console.log(dateValues); // 👉️ "09/24/2022" console.log(timeValues); // 👉️ "07:30:14" const [month, day, year] = dateValues.split('/'); const [hours, minutes, seconds] = timeValues.split(':'); const date = new Date( +year, month - 1, +day, +hours, +minutes, +seconds, ); // 👇️️ Sat Sep 24 2022 07:30:14 console.log(date); // 👇️ "2022-09-24T04:30:14.000Z" (ISO 8601) console.log(date.toISOString()); 

The toISOString method returns a string of the date in the ISO 8601 format according to universal time.

The ISO string can easily be passed to the Date() constructor to create a new Date object.

# Convert a String to a Date using date-fns

You can also use the date-fns module to convert a string to a Date.

First, make sure you have the module installed by running the following command from the root directory of your project.

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# 👇️ with NPM npm install date-fns # 👇️ with YARN yarn add date-fns 

Now you can import and use the parse() function from the date-fns module.

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import parse> from 'date-fns'; const str = '12/21/2024 06:34:59'; const date = parse(str, 'MM/dd/yyyy hh:mm:ss', new Date()); console.log(date); // 👉️ 2024-12-21T06:34:59.000Z 

The code sample assumes that you have a Date string formatted as MM/DD/yyyy hh:mm:ss .

The parse function takes a date or date and time string and converts the string to a Date object.

You can view the accepted format string patterns in this table in the docs.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

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