How to Convert Timestamps to Dates in JavaScript

let timestamp = 1609459200; // Unix timestamp in seconds
let date = new Date(timestamp * 1000); // JavaScript uses milliseconds
let formattedDate = date.toLocaleDateString();
console.log(formattedDate);

Using the Date constructor

The JavaScript Date constructor can be used to convert a timestamp (in milliseconds) to a human-readable date format. As an example, consider a timestamp ‘1617988557000’, we can convert this timestamp into a date format like ‘2021-04-09T09:42:37.000Z’

var timestamp = 1617988557000; //sample timestamp in milliseconds
var date = new Date(timestamp); //converting timestamp to date
console.log(date.toISOString()); //logging the date in 'YYYY-MM-DDTHH:MM:SS.sssZ' format

How it works

This code snippet works by first defining a timestamp. It then uses the JavaScript Date constructor to convert this timestamp into a date object. Finally, it uses the built-in method ‘toISOString()’ to convert this date object into a readable string format ‘YYYY-MM-DDTHH:MM:SS.sssZ’.

• The JavaScript Date constructor takes a timestamp as an argument and returns a Date object. In the provided code, we are passing ‘timestamp’ as an argument which represents the number of milliseconds since the Unix Epoch (January 1, 1970, 00:00:00 UTC).
• This Date object represents a single moment in time, which can be retrieved using various built-in methods. Here, ‘toISOString()’ method is used which returns a string in simplified extended ISO format (ISO 8601), which is always 24 or 27 characters long (YYYY-MM-DDTHH:mm:ss.sssZ or ±YYYYYY-MM-DDTHH:mm:ss.sssZ, respectively). The timezone is always zero UTC offset, as denoted by the suffix “Z” which stands for “zero meridian”.
• The ‘console.log()’ function is used to print this ISO string to the console.

Using the toLocaleDateString() method

The toLocaleDateString() method in JavaScript is used to convert a timestamp into a more human-readable date format based on the locale of the user’s browser. To better understand this, consider the following example where we convert a Unix timestamp into a date:

let timestamp = 1609459200; // Unix timestamp in seconds
let date = new Date(timestamp * 1000); // JavaScript uses milliseconds
let formattedDate = date.toLocaleDateString();
console.log(formattedDate);

How it works

The toLocaleDateString() method works by converting a Date object into a string, using the language and formatting conventions of the user’s locale (the region and language settings of their browser).

• First, we create a variable timestamp and assign it a Unix timestamp value. A Unix timestamp is a way of tracking time as a running total of seconds that have elapsed since the Unix Epoch (1st January 1970 at UTC). This timestamp is considered a universal format across different systems.
• Next, we create a new Date object. However, the JavaScript Date object is based on a time value that is milliseconds since the Unix Epoch, so we have to multiply the Unix timestamp by 1000.
• We then use the method toLocaleDateString() on the Date object. This will give us a string representation of the date, formatted according to the user’s locale.
• Finally, we log the formatted date to the console to verify that the conversion has been successful.

Using Moment.js library

We’ll be using the Moment.js library to convert UNIX timestamps into human-readable date formats. To make this concept clearer, we will illustrate it with an example where a UNIX timestamp is converted into a date format like “YYYY-MM-DD HH:mm:ss”.

var moment = require('moment');
var timestamp = 1633024268; //UNIX timestamp
var convertedDate = moment.unix(timestamp).format('YYYY-MM-DD HH:mm:ss');

console.log(convertedDate);

How it works

The provided JavaScript code leverages the Moment.js library to convert a UNIX timestamp into a date format. The UNIX timestamp signifies the number of seconds that have passed since January 1, 1970, at 00:00:00 UTC (minus leap seconds). The moment.unix() function parses this timestamp, and the format() function then converts it into a readable date/time format.

• Step 1: We import the Moment.js library using the require() function.
• Step 2: We declare a variable named ‘timestamp’ and set it to a UNIX timestamp.
• Step 3: In order to convert the UNIX timestamp into a readable date format, we use the ‘moment.unix()’ function to parse the UNIX timestamp. The ‘format()’ function is then applied to present the date and time in the ‘YYYY-MM-DD HH:mm:ss’ format.
• Step 4: Finally, we use ‘console.log()’ to print the converted date in the console.