What is a Unix timestamp?

A Unix timestamp, also called epoch time, is the number of seconds that have elapsed since January 1 1970 00:00:00 UTC, not counting leap seconds. It is a single number that represents a moment in time independent of timezone, which is why it is the standard way computers store and exchange dates internally.

What is the Year 2038 problem?

The Year 2038 problem occurs because many older systems store Unix time as a signed 32-bit integer, which can only count up to 2,147,483,647 seconds past the epoch. At 03:14:07 UTC on January 19 2038, that counter overflows and wraps around to a negative number, which can cause dates to roll back to 1901 on systems that have not moved to 64-bit time values.

How many digits is a Unix timestamp in seconds vs milliseconds?

A current Unix timestamp in seconds is 10 digits long. In milliseconds it is 13 digits, in microseconds it is 16 digits, and in nanoseconds it is 19 digits. Counting the digits is a quick way to guess which unit a timestamp is in before converting it.

What timezone is Unix time in?

A Unix timestamp itself has no timezone. It is always a count of seconds from UTC midnight on January 1 1970. Timezone only enters the picture when you convert that number into a human-readable date, at which point you choose whether to render it in UTC, your local timezone, or any other IANA timezone.

OpsBash.com ⚡ Free Tools

Buy me a Koffee

Free Unix Timestamp Converter

Unix Timestamp Converter

Q: Why do my application logs show a giant number instead of a date?

Many logging libraries and runtimes, including Node.js Date.now(), Python's time.time(), and Java's System.currentTimeMillis(), record timestamps as raw epoch milliseconds rather than formatted dates. This is timezone safe, sorts correctly as plain numbers, and avoids parsing ambiguity, but it means humans reading raw logs need a converter to make sense of the value.

Convert epoch timestamps to human dates and back. Auto-detects seconds, milliseconds, microseconds and nanoseconds. Everything runs locally in your browser.

Epoch to Human Date

Unix Timestamp

UTC Datetime

—

Local Datetime

—

ISO 8601

—

Relative

—

Human Date to Epoch

Date

Time

Timezone

Seconds

—

Milliseconds

—

Microseconds

—

Nanoseconds

—

Microsecond and nanosecond values are derived from millisecond precision and shown for convenience.

Current Timestamp

Seconds

—

Milliseconds

—

Batch Converter

Paste timestamps, one per line (mixed formats allowed)

Frequently Asked Questions

Many logging libraries and runtimes, including Node.js Date.now(), Python's time.time(), and Java's System.currentTimeMillis(), record timestamps as raw epoch milliseconds rather than formatted dates. This is timezone safe, sorts correctly as plain numbers, and avoids parsing ambiguity, but it means humans reading raw logs need a converter to make sense of the value. Paste any of those raw values into the converter above to see the human date instantly.

What is Epoch Time?

Epoch time, or Unix time, counts the number of seconds since January 1 1970 00:00:00 UTC, known as the Unix epoch. It is the universal internal representation of time used by nearly every operating system, database, and programming language because a single number sorts correctly, compares correctly, and carries no timezone ambiguity. Higher resolution variants in milliseconds, microseconds, and nanoseconds are common in logging and tracing systems where sub-second precision matters.

Why Timestamps Show Up in Logs

Structured logs, distributed traces, and database rows almost always record time as epoch milliseconds or seconds rather than a formatted date string, and that's a deliberate choice, not a missing feature. Comparing two integers is faster than parsing and comparing two date strings, and at the scale of millions of log events per second, or billions of rows accumulated over time, that difference adds up to real CPU time and real storage cost. A 10-digit integer is smaller than a formatted datetime string repeated across every row in a table.

The deeper reason is timezone neutrality. An epoch number has no timezone attached to it: 1718400000 means the exact same instant whether it's read in Mumbai, London, or São Paulo. The moment you format that as a string like 2024-06-14 16:00:00 you've introduced a question the raw number never had, which timezone is that, UTC, IST, local server time. Epoch sidesteps the question entirely by being an absolute value with no regional interpretation, which is also why a timestamp written by a Go service can be read by a Python pipeline without any format negotiation between them.

That convenience pushes a real cost onto whoever reads the logs later: figuring out which precision you're looking at. A 10-digit number is seconds, 13 digits is milliseconds, 16 is microseconds, 19 is nanoseconds, the same instant expressed at different resolutions. The classic mistake is treating a millisecond value as seconds. Paste a 13-digit timestamp into a naive converter without dividing by 1000 first and you land on a date somewhere around the year 56,000 instead of today. Checking the digit count before converting takes two seconds and saves the confused debugging session that follows from getting it wrong. Pasting the raw number into the converter above does that digit-counting for you automatically.

Seconds, Milliseconds, Microseconds, Nanoseconds

The same instant in time can be expressed at different resolutions: 10-digit seconds, 13-digit milliseconds, 16-digit microseconds, or 19-digit nanoseconds. JavaScript's Date.now() returns milliseconds, Python's time.time() returns seconds as a float, and Go's time.UnixNano() returns nanoseconds. Knowing the digit count of a raw value is usually enough to identify which unit you are looking at.

The Year 2038 Problem in Practice

Systems that still represent time as a signed 32-bit integer will overflow at 03:14:07 UTC on January 19 2038. Most modern 64-bit systems have already moved past this limit, but embedded devices, old database schemas, and legacy file formats can still be affected. If you are scheduling events far into the future, it is worth checking how the underlying system stores time. Need to schedule that far-future job? Try the Cron Expression Generator to build the schedule once you know the date is safe.