Sometimes, we want to calculate the UTC offset given a time zone string in JavaScript.
In this article, we’ll look at how to calculate the UTC offset given a time zone string in JavaScript.
Calculate the UTC Offset Given a Time Zone String in JavaScript
To calculate the UTC offset given a time zone string in JavaScript, we can use the JavaScript date’s toLocaleString method to get the time zone offset.
For instance, we can weite:
const getTimezoneOffset = (d, timeZone) => {
const a = d.toLocaleString("ja", {
timeZone
}).split(/[/s:]/);
a[1]--;
const t1 = Date.UTC(...a);
const t2 = new Date(d).setMilliseconds(0);
return (t2 - t1) / 60 / 1000;
}
console.log(getTimezoneOffset(new Date(2016, 0, 1), "America/New_York"))
to create the getTimezoneOffset function that takes the d date and timeZone .
We get the date parts in an array with the toLocaleString method which we called with the timeZone .
Then we subtract the month number by 1 to match the JavaScript convention with:
a[1]--;
Next, we call Date.UTC with the a array spread as the arguments to create t1
Then we create t2 with 0 milliseconds.
Next, we subtract t2 and t1 and divide that by 60 seconds and return that.
Now we get the time zone offset in minutes.
Conclusion
To calculate the UTC offset given a time zone string in JavaScript, we can use the JavaScript date’s toLocaleString method to get the time zone offset.
