Convert a Date string to a Timestamp using JavaScript

Convert a Date string to a Timestamp using JavaScript #

To convert a date string to a timestamp:

1. Pass the date string to the Date() constructor.
2. Call the getTime() method on the Date object.
3. The getTime method returns the number of milliseconds since the Unix Epoch.

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// ✅ with Date formatted as YYYY-MM-DD
const dateStr1 = '2022-06-24';

const date1 = new Date(dateStr1);

const timestamp = date1.getTime();
console.log(timestamp); // 👉️ 1656028800000

// 👇️ If you need to convert milliseconds to seconds
// divide by 1000
const inSeconds = Math.floor(date1.getTime() / 1000);

// ✅ with Date in other format, e.g. MM/DD/YYYY
const dateStr = '06/24/2022';

const [month, day, year] = dateStr.split('/');

const date2 = new Date(+year, month - 1, +day);
console.log(date2);

In the first example, we have a date string formatted as YYYY-MM-DD, so we are able to directly pass the date string as a parameter to the Date() constructor to get a Date object.

To get a timestamp, we called the getTime method on the Date object.

If you need to convert the timestamp to seconds, divide the number by 1000.

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const dateStr1 = '2022-06-24';

const date1 = new Date(dateStr1);

const timestamp = date1.getTime();
console.log(timestamp); // 👉️ 1656028800000

// 👇️ If you need to convert milliseconds to seconds
// divide by 1000
const inSeconds = Math.floor(date1.getTime() / 1000);

If your date string cannot be passed directly to the Date() constructor, split it on the separator and pass the date components as parameters to the Date() constructor.

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// ✅ with Date in other format, e.g. MM/DD/YYYY
const dateStr = '06/24/2022';

const [month, day, year] = dateStr.split('/');

const date2 = new Date(+year, month - 1, +day);
console.log(date2); // 👉️ Fri Jun 24 2022

// 👇️ Get timestamp
const timestamp = date2.getTime();

The Date() constructor is most commonly called with a string formatted as ISO 8601 - YYYY-MM-DDTHH:mm:ss.sssZ, or with parameters for the year, month (0 = January, 1 = February, etc.), day of the month, hours, minutes and seconds.

We have a date string formatted as mm/dd/yyyy in the example, but this can be any other format.

We used array destructuring to directly assign the array elements to variables.

And then we passed the values to the Date() constructor.

The month parameter is a zero-based value from 0 (January) to 11 (December), so we had to subtract 1 from the value we got from the date string.

If you also have time-related data, e.g. hours, minutes and seconds, pass them to the Date() constructor as well.

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const dateStr = '06/24/2022 09:30:05';

const [dateRelated, timeRelated] = dateStr.split(' ');
console.log(dateRelated); // 👉️ "06/24/2022"
console.log(timeRelated); // 👉️ "09:30:05"

const [month, day, year] = dateRelated.split('/');
const [hours, minutes, seconds] = timeRelated.split(':');

const date2 = new Date(+year, month - 1, +day, +hours, +minutes, +seconds);
console.log(date2); // 👉️ Fri Jun 24 2022 09:30:05

// 👇️ Get timestamp
const timestamp = date2.getTime();

Then, we repeated the steps from the previous example to get all of the values we need to pass as parameters to the Date() constructor.