About Unix Timestamp Converter

Unix Timestamp Converter translates epoch timestamps — the number of seconds or milliseconds elapsed since January 1 1970 UTC — into human-readable dates and times across any timezone, and converts dates back to Unix timestamps in both units. A live ticking clock always shows the current epoch value, making it easy to grab timestamps on the fly.

The tool also outputs multiple date formats simultaneously (UTC, ISO 8601, RFC 2822, relative time, day-of-week) so you never need to reformat manually. A built-in time difference calculator computes the span between two datetimes in seconds, minutes, hours, days, weeks, and months. All conversions run locally in your browser using Day.js — no data leaves your machine.

Common Use Cases

Debugging API responses or log files that store dates as epoch seconds or milliseconds by translating them to readable local time.
Generating a Unix timestamp for a specific future date to use as a cache expiry, token expiration, or scheduled job trigger in code.
Checking what time a UTC timestamp corresponds to in a specific timezone like America/New_York or Asia/Kolkata without writing timezone conversion code.
Calculating the exact duration between two events — such as an incident start and resolution time — in multiple units for SLA reporting.

How to Use

Select your target timezone from the dropdown or click "Use Local" to automatically detect your browser timezone.
Paste or type a Unix timestamp into the "Unix Timestamp → Date" field; toggle between Seconds and Milliseconds to match your data source.
To go the other direction, pick a date and time using the "Date → Unix Timestamp" date picker and optionally check "Treat input as UTC".
Use the Time Difference Calculator at the bottom to set two datetimes and click Calculate to see the span broken down into multiple units.

Frequently Asked Questions

How do I know if my timestamp is in seconds or milliseconds?

A Unix timestamp in seconds is currently a 10-digit number (around 1,700,000,000 as of 2023). A millisecond timestamp is 13 digits (the same value multiplied by 1000). If your timestamp has 13 digits, switch the toggle to Milliseconds; if it has 10, use Seconds. Some languages like JavaScript use milliseconds by default (Date.now()), while others like Python use seconds (time.time()).

Does the converter handle Daylight Saving Time correctly?

Yes. This tool uses Day.js with the timezone plugin, which relies on the browser's built-in Intl API to resolve UTC offsets including DST transitions. When you select a timezone such as America/New_York, the displayed time automatically reflects whether EST (UTC-5) or EDT (UTC-4) is in effect for the given timestamp.

What is epoch time and why do computers use it?

Epoch time (Unix time) represents a point in time as a single integer — the number of seconds since midnight on January 1 1970 UTC. Computers use it because integers are easy to store, compare, and sort, and because a single number is timezone-agnostic. Converting to a human-readable format only happens at display time, keeping data storage simple and portable across systems.