Timestamp Converter

A Unix timestamp (also known as Epoch time or POSIX time) is a way of tracking time as a running total of seconds. This count starts at the Unix Epoch on January 1st, 1970 at UTC. For example, the timestamp 1609459200 represents January 1st, 2021 at midnight UTC. Unix timestamps are widely used in programming because they're timezone-independent and easy to work with mathematically.

A 10-digit timestamp represents seconds since the Unix Epoch (January 1, 1970), while a 13-digit timestamp represents milliseconds since the same date. JavaScript's Date.now() returns milliseconds (13 digits), while many server-side languages like PHP use seconds (10 digits). Our converter automatically detects which format you're using and handles it appropriately.

The Year 2038 problem (also known as Y2K38 or the Unix Millennium Bug) occurs because many older systems store Unix timestamps as a 32-bit signed integer. The maximum value (2,147,483,647) corresponds to January 19, 2038 at 03:14:07 UTC. After this moment, these systems will overflow and potentially interpret the time as December 13, 1901. Modern systems use 64-bit integers, which can handle dates billions of years into the future.

Unix timestamps are always in UTC (Coordinated Universal Time) and don't include timezone information. The same timestamp represents the exact same moment in time worldwide. When displaying a timestamp as a human-readable date, you apply a timezone offset to show the local time. For example, timestamp 1609459200 is always the same instant, but it displays as different local times in New York vs Tokyo.

Yes, this timestamp converter is completely free to use with no limits or signup required. The conversions are performed using JavaScript's built-in Date object and Intl APIs, which are accurate and reliable. All processing happens in your browser - no data is sent to any server. The tool supports timestamps from the year 1970 onwards and handles both seconds and milliseconds formats.