Convert Unix Timestamp to Date in JavaScript (Step-by-Step Guide)

Figure: Converting Unix Timestamp to Date in JavaScript

Working with timestamps is a common task in modern web development, especially when dealing with APIs, databases, and server logs.
However, Unix timestamps are not human-readable, making them difficult to understand at a glance.

What Is a Unix Timestamp?

A Unix timestamp (Epoch time) represents the number of seconds that have passed since
January 1, 1970 (UTC).

Why Convert Timestamp to Date?

• Display user-friendly dates in UI
• Debug API responses
• Logging and monitoring systems
• Working with databases

Step-by-Step Conversion in JavaScript

const timestamp = 1714556800;
const date = new Date(timestamp * 1000);

console.log(date);

const date = new Date(1714556800 * 1000);
console.log(date.toLocaleString());

const date = new Date(1714556800 * 1000);

const formatted = date.toLocaleDateString("en-US", {
year: "numeric",
month: "long",
day: "numeric"
});

console.log(formatted);

const date = new Date(1714556800 * 1000);
console.log(date.toUTCString());

const now = new Date();
const timestamp = Math.floor(now.getTime() / 1000);

console.log(timestamp);

Common Mistakes

new Date(1714556800)

new Date(1714556800 * 1000)

Real-World API Example

{
"created_at": 1714556800
}

const apiData = { created_at: 1714556800 };

const readable = new Date(apiData.created_at * 1000);

console.log(readable.toLocaleString());

When to Use UTC vs Local

Best Practices

• Always confirm timestamp format (seconds or milliseconds)
• Use UTC for backend systems
• Format dates before displaying
• Create reusable helper functions

Helper Function

function convertTimestamp(ts) {
return new Date(ts * 1000).toLocaleString();
}

console.log(convertTimestamp(1714556800));

FAQs

Final Thoughts

Converting Unix timestamps in JavaScript is simple once you understand the difference between seconds and milliseconds.
Using the correct methods ensures accurate and readable dates in your applications.