Convert Unix timestamp to date and time in JavaScript
David Y.
—The Problem
I have a set of Unix timestamps that I would like to convert into human-readable dates and times. How can I do this in JavaScript?
The Solution
The Unix timestamp is an integer that represents times according to the number of seconds since midnight on the 1st of January, 1970. For example:
- 20 seconds and 13 minutes past 1 am on the 10th of August 2023 can be written as 1691622800.
- 12 seconds and 12 minutes past 12 pm on December 12, 2012 can be written as 1355307132.
- 11 seconds and 11 minutes past 11 am on November 11, 1918 can be written as -1613832529.
To convert these into human-readable dates and times, we can use JavaScript’s Date object. This object’s constructor takes a value similar to a Unix timestamp, but in milliseconds rather than seconds. Therefore, to use a Unix timestamp, we must multiply it by 1000.
const myUnixTimestamp = 1691622800; // start with a Unix timestamp const myDate = new Date(myUnixTimestamp * 1000); // convert timestamp to milliseconds and construct Date object console.log(myDate); // will print "Thu Aug 10 2023 01:13:20" followed by the local timezone on browser console
As shown above, printing out a Date object will show its date and time in a standard, human-readable format. Built-in methods are available for formatting it in ISO-standard format (a simplified version of ISO 8601) and according to the user’s locale (e.g. showing D-M-Y for European users and M-D-Y for American users).
console.log(myDate.toISOString()); // will print "2023-08-10T01:13:20.000Z" console.log(myDate.toLocaleString()); // output will vary based on system locale settings
We can use other methods to output only the date or only the time components:
console.log(myDate.toDateString()); // will print "Thu Aug 10 2023" console.log(myDate.toTimeString()); // will print "01:13:20" followed by the local timezone
Finally, we can also use this Date object to retrieve and output individual parts of the date or time using its instance methods.
console.log(myDate.getFullYear()); // will print 2023 console.log(myDate.getMonth()); // will print 7 (August; January would be 0) console.log(myDate.getDate()); // will print 10 console.log(myDate.getHours()); // will print 1 console.log(myDate.getMinutes()); // will print 13 console.log(myDate.getSeconds()); // will print 20
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