What Is This Tool?
A Unix timestamp (also called epoch time) is the number of seconds elapsed since January 1, 1970, 00:00:00 UTC. It's the standard way computers store points in time: databases, log files, APIs and programming languages all use it because it's a single unambiguous number with no timezone confusion.
Two flavors exist: seconds (10 digits today, e.g. 1720500000) and milliseconds (13 digits, used by JavaScript and Java). This tool detects which one you pasted automatically.
Why Use It?
- Read timestamps from logs, database rows and API responses instantly.
- Auto-detects seconds vs milliseconds — no guessing.
- Shows local time, UTC, ISO 8601 and relative time ("3 hours ago") together.
- Convert in both directions: timestamp → date and date → timestamp.
- Live current-epoch clock for quick reference.
How to Use
- To decode: paste a timestamp (like 1720500000) into the left box and click "Convert".
- Read the result in your local timezone, UTC, ISO 8601 and as relative time.
- To encode: pick a date and time in the right box and click "Convert" to get its timestamp in seconds and milliseconds.
- Use the live clock at the top when you just need the current timestamp.
Example
Input
1720500000Output
Local time: 7/9/2024, 1:20:00 PM
UTC time: Tue, 09 Jul 2024 05:20:00 GMT
ISO 8601: 2024-07-09T05:20:00.000ZA 10-digit value is treated as seconds; a 13-digit value as milliseconds.
Frequently Asked Questions
How does the tool know if my timestamp is in seconds or milliseconds?
By size. Values of 1,000,000,000,000 (1e12) or larger are treated as milliseconds; smaller values as seconds. Current dates are ~1.7 billion in seconds and ~1,700 billion in milliseconds, so the two ranges don't overlap for realistic dates.
Why does my timestamp show a different hour than I expect?
Timezones. A timestamp is always UTC-based; the "local time" row converts it to your device's timezone. Compare the UTC row with what your source system logs — many servers log in UTC.
What is the year 2038 problem?
Systems storing timestamps as signed 32-bit integers overflow on January 19, 2038. Modern systems use 64-bit integers and are unaffected. This tool uses JavaScript numbers, which handle dates far beyond 2038.
Can I convert negative timestamps?
Yes. Negative timestamps represent dates before January 1, 1970 — for example, -86400 is December 31, 1969.
Does the epoch include leap seconds?
No. Unix time pretends every day has exactly 86,400 seconds and ignores leap seconds — a deliberate simplification that keeps arithmetic easy.