Convert date to another timezone in JavaScript

Question

I am looking for a function to convert date in one timezone to another.

It need two parameters,

• date (in format "2012/04/10 10:10:30 +0000")
• timezone string ("Asia/Jakarta")

The timezone string is described in http://en.wikipedia.org/wiki/Zone.tab

Is there an easy way to do this?

Answer 1

Here is the one-liner:

function convertTZ(date, tzString) {
    return new Date((typeof date === "string" ? new Date(date) : date).toLocaleString("en-US", {timeZone: tzString}));   
}

// usage: Asia/Jakarta is GMT+7
convertTZ("2012/04/20 10:10:30 +0000", "Asia/Jakarta") // Tue Apr 20 2012 17:10:30 GMT+0700 (Western Indonesia Time)

// Resulting value is regular Date() object
const convertedDate = convertTZ("2012/04/20 10:10:30 +0000", "Asia/Jakarta") 
convertedDate.getHours(); // 17

// Bonus: You can also put Date object to first arg
const date = new Date()
convertTZ(date, "Asia/Jakarta") // current date-time in jakarta.