Unix Timestamp Guide: Convert Epoch Time to Date Online

May 15, 2026 · 6 min read

If you've ever worked with databases, APIs, or log files, you've probably encountered a Unix timestamp — that mysterious 10-digit number like 1715040000. What does it mean? How do you read it? And how do you convert it into a human-readable date?

This guide covers everything you need to know about Unix timestamps, including how to use our free online timestamp converter to do the conversion instantly.

What Is a Unix Timestamp?

A Unix timestamp (also called epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC — the "Unix Epoch."

For example:

Timestamps are timezone-independent. A Unix timestamp represents the same moment everywhere in the world — which makes them incredibly useful for storing and exchanging time data across systems.

Seconds vs. Milliseconds: What's the Difference?

You'll encounter two common formats:

FormatLengthExampleCommon In
Seconds (10-digit)101715040000PHP, Python, MySQL, most APIs
Milliseconds (13-digit)131715040000000JavaScript (Date.now()), Java, C#

Our timestamp converter automatically detects whether you've entered seconds or milliseconds and converts accordingly.

How to Convert a Timestamp to a Date

The easiest way is to use our online converter — just paste your timestamp and get the date instantly. But here's how it works in different programming languages:

JavaScript

// Timestamp in seconds → Date
new Date(1715040000 * 1000);
// → Tue May 07 2024

// Timestamp in milliseconds → Date
new Date(1715040000000);
// → Tue May 07 2024

// Current timestamp
Math.floor(Date.now() / 1000);  // seconds
Date.now();                      // milliseconds

Python

import datetime

# Timestamp → Date
dt = datetime.datetime.fromtimestamp(1715040000)
print(dt)  # 2024-05-07 00:00:00

# Date → Timestamp
ts = int(datetime.datetime.now().timestamp())
print(ts)

PHP

<?php
// Timestamp → Date
echo date('Y-m-d H:i:s', 1715040000);

// Date → Timestamp
echo strtotime('2024-05-07 00:00:00');
?>

MySQL

-- Timestamp → Date
SELECT FROM_UNIXTIME(1715040000);

-- Date → Timestamp
SELECT UNIX_TIMESTAMP('2024-05-07');

How to Convert a Date to a Timestamp

You can enter any date in our converter tool and get the corresponding timestamp in both seconds and milliseconds. The tool supports:

Common Timestamp Use Cases

Time Zone Handling

A common source of bugs: forgetting that Unix timestamps are always UTC. When you convert a timestamp to a date, you need to consider the time zone:

Frequently Asked Questions

Why 1970?

January 1, 1970, was chosen as the "epoch" for Unix time because early Unix developers needed a simple, consistent starting point. It's arbitrary but universally adopted.

What happens in 2038?

The Year 2038 Problem (Y2K38) will occur when 32-bit systems overflow at 03:14:07 UTC on January 19, 2038. Most modern systems use 64-bit integers, avoiding this issue — but legacy systems may still be affected.

Can timestamps be negative?

Yes! Negative timestamps represent dates before January 1, 1970. For example, -86400 = December 31, 1969.

What's the maximum future timestamp?

For 32-bit systems: 2147483647 (January 19, 2038). For 64-bit systems: effectively infinite (billions of years).

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