Unix Timestamp Calculator

What Is the Unix Timestamp Calculator?

The Unix Timestamp Calculator is a free online tool for converting between Unix timestamps and UTC dates and times. A Unix timestamp represents a point in time as the number of seconds that have elapsed since the Unix epoch, which began at 00:00:00 UTC on 1 January 1970.

Unix timestamps are widely used by websites, databases, APIs, programming languages and computer systems because a numeric timestamp provides a consistent way to represent a point in time without storing a local time-zone offset.

Why Use the Unix Timestamp Calculator?

This calculator makes it easy to inspect Unix timestamps, convert dates into epoch time and check timestamps used in technical systems, applications and data.

How to Use the Unix Timestamp Calculator

The calculator supports conversion in both directions, allowing you to work with either a Unix timestamp or a UTC date and time.

1. Enter a timestamp — Enter a Unix timestamp in seconds into the Timestamp to Date field.
2. Convert the timestamp — Select “Convert Timestamp” to display the corresponding UTC date and time.
3. Convert a date — Alternatively, enter a UTC date and time in the Date to Timestamp field and select “Convert Date”.
4. Review the result — The calculator displays the Unix timestamp, UTC date and ISO 8601 representation.

How to Convert a Unix Timestamp

To convert a Unix timestamp into a date and time, the timestamp is interpreted as a number of seconds from the Unix epoch at 00:00:00 UTC on 1 January 1970. For example, a timestamp of 0 represents the beginning of the Unix epoch, while 3,600 represents one hour after the epoch.

Unix timestamps can also contain fractional seconds when greater precision is required. This calculator accepts decimal timestamp values and preserves their fractional component when converting the value to a date and time.

Unix Timestamp Examples

A Unix timestamp of 0 corresponds to 1 January 1970 at 00:00:00 UTC. A timestamp of 86,400 corresponds to 2 January 1970 at 00:00:00 UTC because there are 86,400 seconds in a 24-hour day. A timestamp of 1,000,000,000 corresponds to 9 September 2001 at 01:46:40 UTC.

Unix Time and UTC

Unix time is based on UTC rather than a user's local time zone. The same Unix timestamp therefore represents the same instant worldwide, although the corresponding local clock time can differ depending on the time zone used to display it.

Unix Timestamp Format and Accuracy

The traditional Unix timestamp is expressed in seconds. Some systems use milliseconds instead, which means a millisecond timestamp is generally 1,000 times larger than the equivalent Unix timestamp in seconds. Always check which unit an application or API expects before using a timestamp.

This calculator treats entered timestamps as seconds. Date-to-timestamp conversion is calculated using UTC, so the result does not depend on the computer's local time zone. Browser date support determines the practical range of dates that can be converted.

Frequently Asked Questions