Epoch Converter

Epoch time (also called Unix time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC — a moment known as the Unix Epoch. It is a widely used standard in computing for representing a specific point in time as a single integer, making date arithmetic and sorting straightforward across different systems and time zones.

A standard Unix timestamp counts seconds since the epoch and is typically a 10-digit number (e.g., 1700000000). Millisecond timestamps count thousandths of a second and are 13-digit numbers (e.g., 1700000000000). Many modern APIs and JavaScript environments use milliseconds for greater precision. This converter automatically detects which format you've entered.

This is known as the Year 2038 problem (or Y2038). Systems that store Unix timestamps as a signed 32-bit integer can only represent dates up to January 19, 2038 at 03:14:07 UTC. After that point, the value overflows and wraps around, potentially causing errors. Modern 64-bit systems are not affected, as they can store timestamps far into the future.

No — a Unix timestamp is always based on UTC (Coordinated Universal Time) and does not change regardless of your local time zone. When you convert a timestamp to a human-readable date, however, you can display it in any time zone. The underlying timestamp value itself is globally consistent.

Fill in the Year, Month, Day, Hour, Minutes, and Seconds fields in the 'Date to Epoch' section of this tool. The calculator will treat the date as UTC and compute the corresponding Unix timestamp in both seconds and milliseconds. You can also enter an existing timestamp in the top field to convert it back to a readable date.

UTC (Coordinated Universal Time) is a time standard used as the basis for civil time worldwide. Epoch time is a specific numeric representation — the count of seconds since January 1, 1970 UTC. They are related: epoch time is always measured relative to UTC midnight on that date, so any epoch timestamp can be expressed as a UTC date and time.

Unix timestamps are used extensively in software development for logging events, storing dates in databases, comparing time differences, scheduling tasks, and communicating between APIs. Because they are simple integers, they are language- and locale-independent, making them ideal for systems that need to exchange date information reliably.

ISO 8601 is an international standard for representing dates and times, typically formatted as YYYY-MM-DDTHH:MM:SSZ (e.g., 2023-11-14T22:13:20Z). The 'T' separates the date and time, and the trailing 'Z' indicates UTC. It is widely used in APIs, XML, and data interchange formats because it is unambiguous and sortable.