Unix Timestamp Converter

Unix Timestamp Converter — Convert Timestamps to Dates Instantly

Working with API logs, database records, or server events and seeing a 10-digit number like 1724544000? That's a Unix timestamp. This Unix timestamp converter translates any Unix timestamp to a human-readable date and time instantly — and converts any date back to a Unix timestamp. It works in both directions, supports seconds and milliseconds, shows your local time, UTC, and ISO 8601 format, and displays the live current timestamp ticking in real time.

Whether you need to convert a Unix timestamp to a date, convert a date to a Unix timestamp, or quickly decode a 13-digit millisecond timestamp from a JavaScript API — this tool handles all of it without writing a single line of code.

What Is a Unix Timestamp?

A Unix timestamp — also called Unix time, epoch time, or POSIX time — is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC. That starting point is called the Unix epoch. Every second that passes, the timestamp increases by exactly 1.

So a timestamp of 0 means exactly midnight UTC on January 1, 1970. A timestamp of 86400 means exactly 24 hours later (86,400 seconds = 1 day). A timestamp of 1724544000 is August 25, 2024 at 00:00:00 UTC.

Unix timestamps are used universally in software because they are timezone-independent, always increasing (making them easy to sort), simple to store as a single integer, and trivial to do arithmetic on — finding the difference between two moments is just subtraction.

Why Does Unix Time Start at January 1, 1970?

The Unix epoch date of January 1, 1970 was chosen by the early developers of the Unix operating system at Bell Labs in the late 1960s and early 1970s. It was not a deeply meaningful date — it was simply a convenient recent point in time that was practical given the computing constraints of the era. The choice stuck because Unix became so widely adopted that every major programming language, operating system, and database followed the same convention.

JavaScript's Date.now(), Python's time.time(), Unix's date +%s, MySQL's UNIX_TIMESTAMP(), and virtually every other system all count from the same origin: January 1, 1970, 00:00:00 UTC.

How to Use This Unix Timestamp Converter

Convert a Unix Timestamp to a Date

1. Paste your Unix timestamp into the Timestamp → Date field (e.g. 1724544000).
2. Select whether it is in seconds (10 digits) or milliseconds (13 digits).
3. Click Convert to Date — your result appears in local time, UTC, ISO 8601, and relative format.
4. Click any Copy button to copy the result to your clipboard.

Convert a Date to a Unix Timestamp

1. Enter your date and time in the Date → Timestamp section.
2. Select whether to interpret the time as local time or UTC.
3. Click Convert to Timestamp — you get the Unix timestamp in both seconds and milliseconds, ready to copy.

How to Convert a Unix Timestamp to a Date (In Code)

If you need to convert a Unix timestamp to a date programmatically, here are the one-liners for the most common languages:

Note: JavaScript stores timestamps in milliseconds. If your timestamp is 13 digits (e.g. 1724544000000), use new Date(timestamp) directly without multiplying by 1000.

How to Convert a Date to Unix Timestamp (In Code)

Going the other direction — converting a date to a Unix timestamp — is equally common when inserting records into a database, setting token expiry times, or querying time-based data.

How to Convert a Unix Timestamp in Excel

Excel does not natively understand Unix timestamps — it uses its own date serial number system starting from January 1, 1900. But converting a Unix timestamp in Excel is straightforward with the right formula.

If your Unix timestamp (in seconds) is in cell A1, enter this in B1:

Then format cell B1 as a date (Format Cells → Date) and it displays the human-readable date.

For millisecond timestamps (13-digit, common from JavaScript APIs):

For timestamps with time (not just date), format the cell as dd/mm/yyyy hh:mm:ss. For AEST timezone (UTC+10), add the offset:

Seconds vs Milliseconds — Unix Timestamp Formats

The most common source of confusion with Unix timestamps is the difference between seconds and milliseconds.

Mixing formats is one of the most common bugs in date handling. If a Unix timestamp converter gives a date thousands of years in the future, you've passed milliseconds where seconds were expected — divide by 1,000 first.

Common Unix Timestamp Reference Values

The Year 2038 Problem

On January 19, 2038 at 03:14:07 UTC, 32-bit systems that store Unix timestamps as signed integers will overflow — rolling the value back to a large negative number representing December 13, 1901. This is called the Year 2038 Problem (or Y2K38).

Most modern systems have already migrated to 64-bit integer storage, which pushes the overflow date approximately 292 billion years into the future. Legacy embedded systems, older databases, and some IoT devices remain vulnerable.

What Is the ISO 8601 Format?

ISO 8601 is the international standard for representing dates and times as text. An example: 2026-08-17T00:00:00Z. It writes date components from largest to smallest (year-month-day), uses a 24-hour clock, and appends "Z" to denote UTC. It is widely used in APIs and data exchange because it is unambiguous, sorts correctly as plain text, and is human-readable. This Unix timestamp converter outputs ISO 8601 alongside local and UTC formats so you can use whichever your system expects.

Unix Timestamp Converter — Frequently Asked Questions