Unix Timestamp Converter: Epoch Time to Date and Back

  • Free
  • No sign-up
  • Runs in your browser
  • Last updated 2026-10-07
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Turn an epoch timestamp into a readable date, or a date into a timestamp, in seconds and milliseconds.

Timestamp to date

Read as
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UTC (ISO 8601)
-
Your local time
-

Date to timestamp

Seconds
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Milliseconds
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Everything you enter is processed in your browser and is never sent to a server.

How to use

  1. To read a timestamp, enter it under Timestamp to date and press Convert. Use Use current time to fill in the present moment.
  2. To get a timestamp, enter a date such as 2023-11-14T22:13:20Z under Date to timestamp and press Convert.
  3. Read the results: UTC in ISO 8601 form, your local time, and the timestamp in seconds and milliseconds.

Examples

1700000000
→ 2023-11-14T22:13:20.000Z (read as seconds)
1700000000000
→ 2023-11-14T22:13:20.000Z (read as milliseconds)
The same moment written in milliseconds.
2023-11-14T22:13:20Z
→ 1700000000 seconds, 1700000000000 milliseconds

How it works

A timestamp in seconds is multiplied by 1000 to get milliseconds, because JavaScript dates count milliseconds since the epoch. The result is turned into a date, shown in UTC as an ISO 8601 string, and in your local time zone using your browser’s regional settings.

For the reverse direction, the date text is parsed by the browser’s date parser, which understands ISO 8601 style input. The result is shown in milliseconds, and in whole seconds by rounding down.

The supported range is exactly 8.64 quadrillion milliseconds either side of 1970, which is roughly 273,000 years. Values outside it are rejected as invalid.

Sources

Frequently asked questions

What is a Unix timestamp?
It is the number of seconds that have passed since 1 January 1970 00:00:00 UTC, the Unix epoch. It is the same everywhere on Earth, so it avoids time zone confusion.
How does the tool tell seconds from milliseconds?
Values with an absolute size of 100 billion (1e11) or more are read as milliseconds, smaller values as seconds. As seconds, 100 billion is the year 5138, so ordinary dates are never misread, but a very early date written in milliseconds, before March 1973, is read as seconds.
How are dates without a time zone read?
A date and time with no offset, such as 2023-11-14T22:13:20, is read in your browser's local time zone. A date only, such as 2023-11-14, is read as midnight UTC. Add Z or an offset like +09:00 to be explicit.
What is the year 2038 problem?
A signed 32-bit integer can count up to 2147483647 seconds, which is 2038-01-19 03:14:07 UTC. Systems that store timestamps in 32 bits overflow after that. This tool works with larger numbers and is not affected.
Is anything sent to a server?
No. All conversions run in your browser.

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