Convert a UNIX Timestamp to a YYYY-MM-DD Format

How can you convert a UNIX timestamp into a date with the YYYY-MM-DD format?

Below are four different methods, one in pure JavaScript and three others using NPM packages.

Let's get started!

Method 1 - Pure JavaScript

First, let's go over a pure JavaScript solution that doesn't require you to import any external NPM package or library:

// convert timestamp to date object
    // convert the timestamp to milliseconds by multiplying it by 1,000
const date = new Date(timestamp * 1000);

// get the current year in YYYY digit format
const year = date.getFullYear();

// get the month in a 2-digit format
    // getMonth() returns an index position of the month in an array.
        // Therefore, we need to add 1 to get the correct month.
    // toLocaleString() converts any single digit months to have a leading zero (i.e. "2" => "02")
let month = date.getMonth() + 1;
month = month.toLocaleString('en-US', { minimumIntegerDigits: 2, useGrouping: false });

// get the current day of the month
    // toLocaleString() converts any single digit days to have a leading zero (i.e. "8" => "08")
let day = date.getDate();
day = day.toLocaleString('en-US', { minimumIntegerDigits: 2, useGrouping: false });

// combine the year, month, and day into one string to create the "YYYY-MM-DD" format
const dateString = `${year}-${month}-${day}`;

// example output: "2023-04-02"

Make sure you replace timestamp with your UNIX timestamp.

Method 2 - Day.js

If you're fine with using an external library, the Day.js NPM package makes this pretty easy:

import dayjs from "dayjs";

const date = dayjs.unix(timestamp).format("YYYY-MM-DD");

// example output: "2023-04-02"

Make sure you replace timestamp with your UNIX timestamp.

Day.js does all the hard work for us! And the size of the package is only 2kb.

Method 3 - Moment.js

Another great NPM package is Moment.js.

It also makes formatting dates quite simple:

import moment from "moment";

moment.unix(timestamp).format("YYYY-MM-DD");

// example output: "2023-04-02"

Make sure you replace timestamp with your UNIX timestamp.

Method 4 - Luxon

Luxon is another good NPM package you could use for this:

import { DateTime } from "luxon";

const date = DateTime.fromSeconds(timestamp);

const formattedDate = date.toFormat("yyyy-LL-dd");

// example output: "2023-04-02"

Make sure you replace timestamp with your UNIX timestamp.

Thanks for reading and happy coding!