What is the 'Unix Epoch'?

The 'Epoch' is the official starting point for Unix time: 00:00:00 UTC on 1 January 1970. A timestamp of '0' represents this exact moment. Timestamps can be negative to represent dates before 1970.

Why are Unix timestamps used in programming?

Timestamps are preferred because they are a simple, language-agnostic integer. They are not affected by timezones or human-readable formats, making them perfect for storing dates in databases, logging events, and exchanging data in APIs.

What's the difference between a timestamp in seconds vs. milliseconds?

A standard Unix timestamp is in seconds (e.g., 1700000000 - 10 digits). Many modern systems, especially JavaScript ( new Date() ), use milliseconds (e.g., 1700000000000 - 13 digits). This tool can convert both.

Unix Timestamp Converter

Convert timestamps to human-readable dates (and back).

Timestamp to Date

Enter a Unix Timestamp (seconds or ms)

Converted Date:

Date to Timestamp

Year

Month

Day

Hour

Min

Sec

Timezone

Converted Timestamp:

Your Security Matters: Client-Side Processing

All time conversions happen in your browser using your local system clock.
Your dates, times, or timestamps are never stored or sent to our servers.
We don't track or monitor your generated content.

What is a Unix Timestamp (or Epoch Time)?

A Unix Timestamp, also known as Epoch Time or POSIX Time, is a system for describing a point in time. It is defined as the total number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970.

This starting point (January 1, 1970) is called the "Unix Epoch".

Why are Unix Timestamps used?
Timestamps are the "mother tongue" of time for computers. Instead of dealing with complex, human-readable date formats (like "Oct 25, 2024" vs "25/10/2024") and timezones, a timestamp is a single, unambiguous integer.

Language Agnostic: A timestamp number is the same in Python, JavaScript, Java, PHP, and SQL.
Timezone Independent: It is always based on UTC. This makes it the perfect format for storing dates in a database or sending them in an API request. The "local time" conversion should only happen at the very end, in the user's browser.

Seconds vs. Milliseconds:

Standard Timestamp (Seconds): A 10-digit number (e.g., 1700000000). Used by Unix, Linux, PHP, Python, and most databases.
Millisecond Timestamp: A 13-digit number (e.g., 1700000000000). Used by JavaScript (new Date().getTime()) and other high-precision systems.

This converter will auto-detect whether your input is in seconds or milliseconds and show you the correct conversion.

Unix Timestamp Examples

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Unix Timestamp Best Practices & Key Concepts

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Seconds vs. Milliseconds

The most common bug. A 10-digit timestamp is in seconds. A 13-digit timestamp is in milliseconds. If you pass a 10-digit (seconds) timestamp to a system expecting milliseconds (like JavaScript's new Date(ts)), your date will be wrong (stuck in 1970).

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Always Store in UTC

The Unix timestamp is, by definition, timezone-less (it's based on UTC). This is its greatest strength. Always store timestamps in your database as a pure integer (BIGINT or INTEGER). Only convert it to a "local time" on the client-side for the user to see.

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The "Y2K38" Problem

The original Unix timestamp was stored as a signed 32-bit integer. This integer will run out of positive numbers and "overflow" (becoming a negative number) on January 19, 2038. This will break older 32-bit systems. Modern systems avoid this by using 64-bit integers, which won't overflow for 292 billion years.