Timestamp to Date Converter

What is a Unix Timestamp?

A Unix timestamp (also called epoch time) is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970 — known as the "Unix epoch." It's a compact, unambiguous way to represent a point in time and is used throughout computing: in databases, APIs, file system metadata, logs, cookies, and JWTs.

Seconds vs. Milliseconds

Unix timestamps come in two common forms: seconds (used by most back-end systems) and milliseconds (used by JavaScript's Date.now() and many APIs). This tool auto- detects which format you pasted based on its size — anything with more than about 12 digits is treated as milliseconds.

How To Use This Tool

On the left, paste a timestamp and see it converted into ISO, UTC, and local time, plus a human-friendly "relative" label like "3 hours ago." On the right, pick a date and time to get the equivalent timestamp in seconds and milliseconds.

Common Use Cases

• Debugging API responses that contain epoch timestamps.
• Reading JWT iat (issued at) and exp (expiration) claims.
• Converting server logs to your local timezone.
• Storing dates as integers in a database for easy sorting and comparison.

The Year 2038 Problem

32-bit signed timestamps overflow on 19 January 2038. Modern systems use 64-bit timestamps and are safe for billions of years, but legacy systems may still be vulnerable. This is the "Y2038" problem — similar in spirit to Y2K.

FAQ

Does this converter support seconds and milliseconds?

Yes. Shorter epoch values are treated as seconds, while values with more than about 12 digits are treated as milliseconds.

Why does local time differ from UTC?

UTC is the global reference time. Local time applies your browser timezone and may include daylight saving time offsets.

Where are Unix timestamps used?

Unix timestamps are common in APIs, logs, databases, cookies, JWT claims, analytics events, and scheduling systems.