Timestamp Converter

Convert Unix timestamps to human-readable dates and back. Supports seconds, milliseconds, and multiple timezones.

UnixDateTimezoneISO 8601
Now (UTC):—
Unix (s):—Unix (ms):—
Unit
Timezone

All processing happens locally in your browser — your data never leaves your device.

Timestamp Converter turns a Unix epoch value into readable dates, and a date string back into an epoch value. Paste 1700000000 from a log line or database column and you get the same instant as Unix seconds, Unix milliseconds, ISO 8601, a UTC string, the time in a timezone you pick, and a rough relative time such as "3 days ago".

In Timestamp to Date mode you choose whether the input is in seconds (the usual Unix format, 10 digits for current dates) or milliseconds (what JavaScript Date.now() and many APIs return, 13 digits). Mixing them up is the most common reason a converted date lands in 1970 or thousands of years in the future.

Date to Timestamp mode accepts anything the browser's Date parser understands, including ISO 8601 with a Z or an offset like +05:30 and RFC 2822 strings. A strip at the top shows the current UTC time and current epoch in seconds and milliseconds, each with a copy button.

Conversions happen in the browser. When you are scheduling jobs rather than decoding times, the cron expression generator previews upcoming run times; for timestamps buried in API payloads, pretty-print the response with the JSON formatter first.

  1. Choose Timestamp → Date or Date → Timestamp.
  2. For Timestamp → Date, select s or ms to match your value, then paste it or click Now to insert the current time.
  3. Optionally pick a timezone from the dropdown to add a row showing the time in that zone.
  4. For Date → Timestamp, type a date string such as 2024-01-15T12:00:00Z.
  5. Press Enter or click Convert, then copy any row in the Result panel with its copy button.

  • Converts in both directions: epoch to date and date string to epoch
  • Seconds and milliseconds input units
  • Results as Unix seconds, Unix milliseconds, ISO 8601, UTC and relative time
  • Timezone view for 12 zones, including UTC, New York, London, Berlin, Kolkata, Tokyo and Sydney
  • Live clock with the current UTC time and epoch values
  • Now button and copy buttons on every result row
  • No server round-trip; all conversion is done in the browser

Unix seconds to date

Input (s): 1700000000

ISO 8601:     2023-11-14T22:13:20.000Z
UTC:          Tue, 14 Nov 2023 22:13:20 GMT
Asia/Kolkata: 11/15/2023, 03:43:20

The same instant shown in UTC and in India Standard Time, which is already the next calendar day.

Milliseconds from JavaScript

Input (ms): 1700000000000

Unix (seconds): 1700000000
ISO 8601:       2023-11-14T22:13:20.000Z

Switch the unit to ms for values from Date.now(), Java System.currentTimeMillis() or most JavaScript APIs.

ISO date string to epoch

Input: 2024-01-15T12:00:00Z

Unix (seconds):      1705320000
Unix (milliseconds): 1705320000000
UTC:                 Mon, 15 Jan 2024 12:00:00 GMT

The trailing Z marks the time as UTC, so the result is the same wherever you run it.

"Invalid number"

The Timestamp field contains letters, a thousands separator or other non-numeric text.

Paste only the digits (a leading minus sign or a decimal fraction is fine).

Converted date is in January 1970

A 10-digit seconds timestamp was converted with the unit set to ms, so it was treated as only a few weeks after the epoch.

Check the unit toggle. A 10-digit value belongs in s mode and a 13-digit value in ms mode.

Converted year is far in the future

A 13-digit milliseconds value was converted with the unit set to seconds.

Switch the unit to ms and convert again.

"Invalid date string"

The browser could not parse the format, typically a locale-specific layout like 15.01.2024.

Rewrite it in ISO 8601, for example 2024-01-15T12:00:00Z.

Result is off by a few hours

The date string had no timezone, so it was interpreted in your local time instead of UTC.

Append Z for UTC or an explicit offset such as -05:00.

What is a Unix timestamp?

It is the number of seconds elapsed since 1970-01-01 00:00:00 UTC (the Unix epoch), ignoring leap seconds. Because it is timezone-independent, it is a common way to store and exchange moments in time. Negative values represent dates before 1970.

How do I tell seconds from milliseconds?

For dates between 2001 and 2286, a seconds timestamp has 10 digits and a milliseconds timestamp has 13. If the result lands in January 1970, a seconds value was read as milliseconds; if it lands tens of thousands of years ahead, a milliseconds value was read as seconds. Switch the unit and convert again.

Which timezone is used when my date string has no offset?

Your browser's local timezone. A string like 2024-01-15 12:00 is read as local time, while a date-only ISO string like 2024-01-15 is read as midnight UTC. The Timezone dropdown only changes how Timestamp → Date results are displayed, not how date strings are parsed, so add Z or an explicit offset for predictable results.

What date formats can I enter?

Whatever the JavaScript Date parser accepts. ISO 8601 (2024-01-15T12:00:00Z, 2024-01-15T17:30:00+05:30) and RFC 2822 (Mon, 15 Jan 2024 12:00:00 GMT) are reliable across browsers. Locale formats such as 15/01/2024 are ambiguous and may be rejected or misread.

How precise is the relative time?

It is a rough guide, rounded down to minutes, hours, days, or 30-day months. Use the ISO or UTC rows for exact values.