Converting UTC to Local Time in JavaScript

When working with APIs, timestamps often come in UTC format, which can be confusing for users expecting local time. JavaScript makes it surprisingly easy to convert UTC to a specific time zone using toLocaleString().

Here’s a practical example:

const utcDate = new Date(“2025-09-08T15:00:00Z”); const localDate = utcDate.toLocaleString(“en-US”, { timeZone: “America/Los_Angeles” }); console.log(localDate); // “9/8/2025, 8:00:00 AM”

Why This Matters

• "2025-09-08T15:00:00Z" is 3:00 PM UTC.
• In Pacific Time, that’s 8:00 AM (due to daylight saving time).
• This method ensures your app displays time correctly for users in different regions.

Pro Tips

• You can change "America/Los_Angeles" to any valid IANA time zone string (e.g., "Asia/Kolkata", "Europe/London").
• Use toLocaleString() for formatted output, or toLocaleTimeString() / toLocaleDateString() for more control.