UNIX Timestamp to Date Converter (free, online)

Convert Unix timestamps to readable dates and date/time values back to epoch seconds or milliseconds. Results include UTC, your browser's local time, ISO 8601, and relative time.

Current Unix Time

Convert Timestamp or Date

Enter epoch seconds, epoch milliseconds, or an ISO/common date value.

Auto treats numeric values below 100 billion in magnitude as seconds; larger values as milliseconds.

Only applies to values such as 2025-06-04 12:30:00 that contain no Z or UTC offset.

Quick:

All conversion happens locally in your browser. No timestamp or date value is uploaded to Flipper File.

Free Unix Timestamp to Date Converter

A Unix timestamp represents an instant as elapsed time from the Unix epoch: January 1, 1970 at 00:00:00 UTC. This tool converts epoch seconds or milliseconds into readable UTC and local dates, and converts date/time values back into Unix timestamps.

Common Unix Timestamp Examples

Epoch seconds1717526400Traditional Unix time in seconds.
Epoch milliseconds1717526400123Common in JavaScript and browser APIs.
ISO 86012025-09-04T14:00:00ZThe Z explicitly means UTC.
Local date/time2025-09-04 14:00:00Interpreted using the timezone option above.
Negative timestamp-315619200Represents a date before the Unix epoch.

How to Convert a Unix Timestamp

  1. Paste epoch seconds or milliseconds into the input box.
  2. Leave Input type on Auto-detect, or choose the unit explicitly if the number is unusual.
  3. Click Convert to see epoch seconds, milliseconds, UTC, local time, ISO 8601, and relative time.
  4. Use the copy buttons or quick adjustments as needed.

How Date Parsing Works

ISO 8601 values with Z or a numeric offset are interpreted using that explicit timezone. A date such as 2025-09-04 14:00:00 contains no timezone, so you can choose whether it should mean your browser's local time or UTC. The converter uses strict handling for common year-month-day formats rather than relying only on browser-specific parsing behavior.

Seconds vs. Milliseconds

Traditional Unix time counts seconds. JavaScript's Date API uses milliseconds. A current seconds timestamp is about 10 digits while a current milliseconds timestamp is about 13 digits. Auto-detection uses the numeric magnitude, while the explicit input-type selector is available for edge cases and dates far from the present.

UTC vs. Local Time

A Unix timestamp itself does not contain a timezone: it identifies one instant. UTC and local time are simply different representations of that same instant. The Local result uses the timezone configured in your browser or operating system.

Common Unix Timestamp Examples

  • Epoch Seconds
    1717526400
    Example: Tue, 04 Jun 2024 00:00:00 UTC
  • Epoch Milliseconds
    1717526400123
    Example: Tue, 04 Jun 2024 00:00:00.123 UTC
  • ISO 8601 Date String
    2025-09-04T14:00:00Z
    Example: Converts to 1756658400 (epoch seconds)
  • Human-Friendly Date
    2025-09-04 14:00:00
    Example: Parses as local time → UTC equivalent shown
  • Negative Timestamp
    -315619200
    Example: Fri, 01 Jan 1960 00:00:00 UTC

These examples show the different formats you can use in the converter. The tool auto-detects whether the input is epoch seconds, epoch milliseconds, or a date string (ISO or common formats), and instantly shows the equivalent UTC, local, ISO, and relative time.

Unix Timestamp Converter FAQ

What is a Unix timestamp?

A Unix timestamp (or epoch time) is the number of seconds that have passed since January 1, 1970 at 00:00:00 UTC. It’s a standard way to represent time in programming and computer systems.

What is the difference between seconds and milliseconds?

Unix timestamps are traditionally stored as seconds. Some systems (like JavaScript) use milliseconds, which are 1/1000th of a second. This tool automatically detects whether you entered seconds or milliseconds.

Which time zone is used?

The converter always shows UTC time for consistency, and also provides your system’s local time side by side.

Can I convert dates to timestamps?

Yes. Enter a date in ISO 8601 format (e.g., 2025-09-04T14:00:00Z) or a common format like YYYY-MM-DD HH:mm:ss, and the tool will convert it to epoch seconds and milliseconds.

What happens with negative timestamps?

Negative timestamps represent dates before January 1, 1970. For example, -315619200 converts to January 1, 1960 UTC.

Is my data secure?

All conversions run locally in your browser. No input or output is sent to a server, so your data stays private.

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