Convert a Date to another Time Zone using JavaScript

avatar

Borislav Hadzhiev

Last updated: Jul 25, 2022

banner

Photo from Unsplash

Convert a Date to another Time Zone using JavaScript #

To convert a date to another time zone:

  1. Use the toLocaleString() method to get a string that represents the date according to the provided time zone.
  2. Pass the result to the Date() constructor.
  3. The returned Date object will have its date and time set according to the provided time zone.
index.js
function changeTimeZone(date, timeZone) { if (typeof date === 'string') { return new Date( new Date(date).toLocaleString('en-US', { timeZone, }), ); } return new Date( date.toLocaleString('en-US', { timeZone, }), ); } const laDate = changeTimeZone(new Date(), 'America/Los_Angeles'); console.log(laDate); // 👉️ "Sun Jan 16 2022 01:22:07" const berlinDate = changeTimeZone(new Date(), 'Europe/Berlin'); console.log(berlinDate); // 👉️ "Sun Jan 16 2022 10:22:07"

The toLocaleString method returns a locale-specific string that is adjusted to the provided time zone.

The changeTimeZone function can be passed a date string or a Date object and returns a Date object with the date and time corresponding to the provided time zone.

The two parameters we passed to the toLocaleString method are:

  1. locales - a string with a BCP 47 language tag or an array of such strings. You can use any of the available locales, e.g. es-MX for Mexico or en-CA for Canada. If you need more information about this parameter, check out the MDN docs.
  2. options object where we specified the timeZone property. Read more about the options object in the MDN docs.

You can find a table of the country codes and time zone database names by visiting this wikipedia page.

However, note that the Date object in JavaScript does not store a time zone.

It stores a timestamp that represents the number of milliseconds that have passed since midnight on January 1st, 1970.

The date and time of the Date object correspond to the time zone, however the Date object has no way of storing the specific time zone.

For this reason, it's best to use the toLocaleString method to get a string that represents the time zone and use the options object parameter to format the string according to your needs.

You can use the different properties on the options object of the toLocaleString method to format the date and time for the specific time zone in different ways.

index.js
const date = new Date(); console.log( date.toLocaleString('en-US', { timeZone: 'America/New_York', dateStyle: 'full', timeStyle: 'full', }), ); // 👉️ "Sunday, January 16, 2022 at 4:42:40 AM Eastern Standard Time"

We set the dateStyle and timeStyle properties in the options object to full to get a more verbose representation of the date and time.

Other possible values for the two properties are: long, medium and short.

index.js
const date = new Date(); console.log( date.toLocaleString('en-US', { timeZone: 'America/New_York', dateStyle: 'short', timeStyle: 'short', }), ); // 👉️ "1/16/22, 4:43 AM"

You can view all of the properties and values the options object implements by visiting the MDN docs.

Here is an example that shows the month, day, hours, minutes and seconds as 2-digits, even if their values are less than 10.

index.js
const date = new Date(); console.log( date.toLocaleString('en-US', { timeZone: 'America/New_York', year: 'numeric', month: '2-digit', day: '2-digit', hour: '2-digit', minute: '2-digit', second: '2-digit', timeZoneName: 'short', }), ); // 👉️ "01/16/2022, 04:43:39 AM EST"
By setting the values of the date and time components to 2 digits, we format them consistently, even if they have a value of less than 10.

If that's the case, the values get padded with a leading zero.

We also set the timeZoneName property to a value of short, to show an abbreviation of the time zone name at the end of the result.

You can view all the other properties the options object supports by visiting the MDN docs.

You can get a time zone specific date and time representation formatted in many different ways by just using the toLocaleString method and this should be your preferred approach as it leverages built-in functionality.
I wrote a book in which I share everything I know about how to become a better, more efficient programmer.
book cover
You can use the search field on my Home Page to filter through all of my articles.