Getting The Client’s Time Zone (and Offset) In JavaScript

In JavaScript, you can get the client’s time zone and offset using the Intl.DateTimeFormat and Date objects. Here’s how you can retrieve the client’s time zone and the offset from UTC.

1. Getting the Client’s Time Zone

You can use the Intl.DateTimeFormat object to get the time zone name:

// Get the client's time zone
const timeZone = Intl.DateTimeFormat().resolvedOptions().timeZone;
console.log(timeZone); // Example output: "America/New_York"

This will give you the name of the time zone, such as "America/New_York", "Europe/London", or "Asia/Tokyo".

2. Getting the Client’s UTC Offset

To get the UTC offset (in minutes) of the client’s local time zone, use the Date object’s getTimezoneOffset() method.

// Get the client's UTC offset in minutes
const date = new Date();
const utcOffsetMinutes = date.getTimezoneOffset();
console.log(utcOffsetMinutes); // Example output: -300 (UTC-5 hours)

The getTimezoneOffset() method returns the difference between the client’s local time and UTC in minutes. Positive values indicate that the local time zone is ahead of UTC, and negative values indicate that it is behind UTC.

3. Getting the UTC Offset with Hours and Minutes

If you want to display the UTC offset in a more human-readable format (e.g., +02:00 or -05:00), you can do the following:

// Get the client's UTC offset in hours and minutes (formatted as +HH:mm or -HH:mm)
const offset = new Date().getTimezoneOffset();
const sign = offset > 0 ? '-' : '+';
const hours = Math.floor(Math.abs(offset) / 60);
const minutes = Math.abs(offset) % 60;
const formattedOffset = `${sign}${String(hours).padStart(2, '0')}:${String(minutes).padStart(2, '0')}`;
console.log(formattedOffset); // Example output: "-05:00"

4. Combining Time Zone and UTC Offset

You can combine both the time zone name and the UTC offset into a single string:

const timeZone = Intl.DateTimeFormat().resolvedOptions().timeZone;
const utcOffset = new Date().getTimezoneOffset();
const sign = utcOffset > 0 ? '-' : '+';
const hours = Math.floor(Math.abs(utcOffset) / 60);
const minutes = Math.abs(utcOffset) % 60;
const formattedOffset = `${sign}${String(hours).padStart(2, '0')}:${String(minutes).padStart(2, '0')}`;

console.log(`Time Zone: ${timeZone}, UTC Offset: ${formattedOffset}`);

Summary of Methods

• Intl.DateTimeFormat().resolvedOptions().timeZone: Gets the time zone name (e.g., "America/New_York").
• new Date().getTimezoneOffset(): Gets the UTC offset in minutes (e.g., -300 for UTC-5).
• Custom formatting for offset: Convert the offset to a +HH:mm or -HH:mm format.