What is a Unix timestamp?

A Unix timestamp is the number of seconds that have passed since 1 January 1970 UTC, excluding leap seconds. It is widely used in programming to represent a point in time.

Why are there seconds and milliseconds?

Unix time is traditionally in seconds. JavaScript and many modern systems use milliseconds — the same moment in time multiplied by 1000. Pick the unit that matches your source.

ISO 8601 is an international standard for representing dates and times, e.g. 2025-01-15T10:30:00Z. The trailing Z means UTC. It is the recommended format for APIs and data exchange.

Does the converter use my timezone?

The timestamp itself is timezone-agnostic (always UTC). Local time display uses your browser's timezone. Other formats (ISO, UTC) are shown in UTC.

What is the Year 2038 problem?

Systems that store Unix time as a signed 32-bit integer will overflow on 19 January 2038, when the timestamp exceeds 2,147,483,647 seconds. Many modern systems already use 64-bit integers, which push the limit billions of years into the future.

Does Unix time account for leap seconds?

No. Unix time is defined as the number of seconds since the epoch excluding leap seconds. This means Unix time is not strictly a count of SI seconds since 1970, but the difference is negligible for most applications.

Timestamp Converter

Convert Unix timestamps to ISO, UTC, local and relative time — and back. Choose seconds or milliseconds, use the quick +/- buttons for hours and days, or paste a whole list of timestamps to convert in one batch.

How to use

Enter a timestamp or date

Type a Unix timestamp, ISO date, or human-readable date.

Choose seconds or milliseconds

Select the unit that matches your source.

Read all formats

See the timestamp converted to ISO, UTC, local time and relative time.

Use batch mode if needed

Convert multiple timestamps at once, one per line.

Current time

2026-10-11T14:44:30.549Z (1791729870s)

SingleBatch

Features

Multiple output formats

Unix seconds, milliseconds, ISO 8601, local time and relative time.

Batch conversion

Convert a list of timestamps in one go.

Quick adjustments

Buttons for -1h, +1h, -1d and Now.

Other timezones

See the timestamp in multiple timezones.

Common use cases

Convert a Unix timestamp to a readable date
Check the current Unix time
Convert an ISO date to a Unix timestamp
Batch-convert log timestamps

Frequently Asked Questions

Related tools

Unit Converter

URL Encoder & Decoder

JSON Formatter & Validator

UUID Generator