Timestamp Converter

Features

• Live current timestamp in seconds and milliseconds
• Automatic detection of seconds versus milliseconds
• Local timezone or UTC
• ISO 8601, RFC 2822 and relative-time output
• Relative description such as “3 days ago”

How to use it

1. Paste a Unix timestamp into the first box.
2. Or pick a date and time to get its timestamp.
3. Switch between your timezone and UTC.
4. Copy every format at once from the button below.

Understanding Unix time

A Unix timestamp counts the seconds since 1 January 1970 at 00:00:00 UTC, a moment called the epoch. Because it is a single integer anchored to UTC, it sidesteps timezones, daylight saving and calendar formatting entirely, which is exactly why it remains the default way to store an instant in databases, log files and APIs.

The main confusion is seconds versus milliseconds. Unix tooling, most databases and JSON APIs use seconds; JavaScript's Date.now() returns milliseconds. A millisecond value interpreted as seconds lands roughly 50,000 years in the future, which is a common and very visible bug. This tool detects the difference by magnitude: values above about 100 billion are almost certainly milliseconds.

Two edge cases are worth knowing. Unix time deliberately ignores leap seconds, so it is not a true count of elapsed SI seconds since the epoch, a leap second repeats the same timestamp value. And systems storing timestamps in a signed 32-bit integer overflow on 19 January 2038, the Year 2038 problem. Most modern systems have moved to 64-bit, but embedded and legacy code has not always followed.