Toolsel

Timestamp Converter

Runs in your browser

Convert between Unix timestamps and human-readable dates, in either direction.

Unix timestamp

Date & time (local)

Interpreted in your browser’s timezone.

What is a Timestamp Converter?

A Unix timestamp counts the number of seconds that have passed since midnight UTC on January 1, 1970 — the "Unix epoch". It is a single number rather than a calendar date, which is exactly why so many systems use it: it sorts numerically, compares with simple arithmetic, and carries no timezone ambiguity of its own.

The one common trap is the unit. Unix time is defined in seconds, but JavaScript's Date object and many web APIs work in milliseconds, and some systems use microseconds or nanoseconds. A timestamp like 1700000000 is seconds (year 2023); the same digits as milliseconds would be sometime in 1970. This tool auto-detects which one you likely meant based on digit count.

How to use it

  1. To convert a timestamp to a date: paste the number into the Timestamp field. It is read as seconds or milliseconds automatically based on length, or set it manually.
  2. To convert a date to a timestamp: use the date and time picker, or paste an ISO 8601 string.
  3. Click Now to fill in the current time in both directions.
  4. Read the result in ISO 8601, UTC, your local timezone, and as a relative time ("3 hours ago") all at once.

Example

Timestamp to date

Input
1700000000
Output
2023-11-14T22:13:20.000Z (UTC)

Frequently asked questions

Why is my 13-digit timestamp showing the wrong date?
It is almost certainly in milliseconds, not seconds — 13 digits is the milliseconds range for dates from 2001 onward, while 10 digits is the seconds range for the same period. Toggle the unit if the auto-detected guess looks wrong.
What happens when Unix time overflows in 2038?
Systems that store the timestamp as a signed 32-bit integer will overflow on January 19, 2038, wrapping to a negative number and effectively jumping back to 1901. Modern systems use 64-bit integers and are unaffected; the risk is mainly in older embedded and legacy software.
Does the converted date depend on my timezone?
The timestamp itself does not — it is a single global instant. This tool shows that instant three ways: in UTC, in your browser's local timezone, and as an ISO 8601 string with an explicit offset, so you can see exactly how the same moment reads in each.
Can timestamps be negative?
Yes. A negative Unix timestamp represents a date before January 1, 1970. -86400, for example, is December 31, 1969. Most parsers and this tool handle negative values correctly.