Unix Timestamp Converter

1. See the current Unix timestamp updating in real time.
2. Enter a timestamp to convert it to a human-readable date.
3. Or enter a date to convert it to a Unix timestamp.
4. Click "Copy" to copy any value.

About Unix Timestamps

A Unix timestamp counts the seconds elapsed since January 1, 1970, 00:00:00 UTC — a date known as the Unix epoch. This tool converts between timestamps and human-readable dates, with support for both seconds and milliseconds precision.

Why January 1, 1970?

The epoch was chosen by early Unix engineers as a convenient, recent-enough starting point. The original Unix system used a 32-bit integer for time, giving a range of about 136 years from 1970. It was a pragmatic choice — close enough to the present to be useful, far enough back to cover historical dates. The entire computing world inherited this convention.

The Year 2038 Problem

Systems using a signed 32-bit integer for Unix time will overflow on January 19, 2038 at 03:14:07 UTC. The counter hits 2,147,483,647 and wraps to a negative number, which represents a date in 1901. Most modern systems use 64-bit integers now, but embedded systems, legacy databases, and older firmware are still at risk. It's the Y2K problem's sequel.

Seconds vs Milliseconds

Unix timestamps traditionally use seconds (10 digits, e.g., 1709913600). JavaScript's Date.now() returns milliseconds (13 digits, e.g., 1709913600000). Java's System.currentTimeMillis() also uses milliseconds. Most REST APIs use seconds. Getting this wrong is a classic bug — if your timestamp looks like it's in the year 55,000, you probably passed milliseconds where seconds were expected.

Always Store in UTC

Store timestamps in UTC and convert to local time only for display. This avoids daylight saving time issues, simplifies sorting and comparison, and makes your data portable across time zones. Unix timestamps are inherently UTC, which is one of their biggest advantages over formatted date strings.