🕑 Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates. View results in ISO 8601, RFC 2822, local, and UTC formats.
Last updated: May 18, 2026 · By Λ
Free Unix Timestamp Converter
Convert Unix timestamps (seconds or milliseconds since January 1, 1970 UTC) to human-readable dates in multiple formats, or convert any date back to a Unix timestamp. View results in ISO 8601, RFC 2822, local time, and UTC. See relative time like "3 hours ago" or "in 2 days". The live clock shows the current Unix timestamp updating every second. The conversions are simple Date arithmetic performed by this page's own script, so nothing you paste is transmitted anywhere.
What is a Unix Timestamp?
A Unix timestamp (also called Epoch time or POSIX time) is a way of tracking time as a running total of seconds. It counts the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC, a date commonly referred to as the "Unix epoch." This system was introduced with the Unix operating system in the early 1970s and has since become a universal standard for representing time in computing. Because it is a single integer, it avoids the complexities of time zones, daylight saving time, and varying calendar formats.
Developers, system administrators, and data analysts regularly need to convert between Unix timestamps and human-readable dates. API responses, log files, database records, and system events frequently store time as Unix timestamps. This online converter makes the translation instant and painless. You can paste a timestamp from a log file, convert it to a readable date, and see results in multiple formats at once. Everything runs in your browser, so your data stays private and the tool works even without an internet connection after the page loads.
How to Use This Tool
- Choose a conversion direction: select "Timestamp to Date" to convert a numeric timestamp into a readable date, or "Date to Timestamp" to go the other way.
- Enter your value. For timestamps, paste or type a number in seconds (10 digits) or milliseconds (13 digits). For dates, use the date and time picker to select a specific moment.
- Click the "Convert" button or use the quick buttons (Now, +1 Hour, +1 Day, +1 Week) to auto-fill and convert common values.
- View the results in all available formats: Unix seconds, Unix milliseconds, ISO 8601, RFC 2822, local time, UTC, and relative time. Click "Copy" next to any format to copy it to your clipboard.
Key Features
- Bidirectional Conversion - Convert timestamps to dates and dates back to timestamps with a single click.
- Auto-Detection - Automatically detects whether your input is in seconds (10-digit) or milliseconds (13-digit) format.
- Multiple Output Formats - View results simultaneously in ISO 8601, RFC 2822, local time, UTC, and relative time (e.g., "3 hours ago").
- Live Clock - A real-time display of the current Unix timestamp updating every second, useful for quick reference.
- 100% Client-Side - Every timestamp you enter is converted on your own device, with no server round trip involved at any point.
Frequently Asked Questions
What is the difference between seconds and milliseconds timestamps?
A Unix timestamp in seconds is a 10-digit number representing the seconds since the epoch. A millisecond timestamp is a 13-digit number representing the milliseconds since the same epoch. JavaScript's Date.now() returns milliseconds, while many server-side languages and tools use seconds. This tool handles both automatically.
What happens at the Year 2038 problem?
The Year 2038 problem occurs because 32-bit systems store Unix timestamps as a signed 32-bit integer, which overflows on January 19, 2038. Modern 64-bit systems and this tool use larger number types, so they can handle dates far beyond 2038 without issues. If you are working with legacy 32-bit systems, it is worth checking that they have been updated.
How does time zone handling work?
Unix timestamps are always based on UTC and do not carry time zone information. When this tool displays "Local Time," it uses your browser's time zone setting to show the equivalent local date and time. The UTC and ISO 8601 outputs always reflect Coordinated Universal Time regardless of your location.
Can I use negative timestamps?
Yes. A negative Unix timestamp represents a date before January 1, 1970. For example, -86400 corresponds to December 31, 1969. This tool supports negative values, so you can convert historical dates that predate the Unix epoch.