Unix Timestamp Converter

A Unix timestamp (also called Epoch time or POSIX time) is a way of tracking time as a running total of seconds. It counts the number of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC, not counting leap seconds. This date is known as the "Unix Epoch." For example, the Unix timestamp 1700000000 corresponds to November 14, 2023 at 22:13:20 UTC.

A standard Unix timestamp is measured in seconds and is typically a 10-digit number (e.g. 1700000000). A millisecond timestamp includes three additional digits for sub-second precision, making it a 13-digit number (e.g. 1700000000000). JavaScript Date.now() returns milliseconds, while many server-side languages and APIs use seconds. This converter auto-detects which format you enter.

The Year 2038 problem (also called the Y2K38 bug or the Epochalypse) is a computing limitation where systems that store Unix time as a 32-bit signed integer will overflow on January 19, 2038 at 03:14:07 UTC. After that moment, the timestamp wraps to a negative number, interpreted as December 13, 1901. Most modern systems have migrated to 64-bit timestamps, which can represent dates billions of years into the future.

In JavaScript: Math.floor(Date.now() / 1000). In Python: import time; int(time.time()). In PHP: time(). In Java: System.currentTimeMillis() / 1000. In Ruby: Time.now.to_i. In Go: time.Now().Unix(). In C: time(NULL). In Bash: date +%s. All of these return the current time as a Unix timestamp in seconds.

Unix timestamps are widely used because they are timezone-independent (always in UTC), easy to compare and sort (simple integer comparison), compact to store (a single number), unambiguous (no date format confusion like MM/DD vs DD/MM), and supported in virtually every programming language and database. They make calculating time differences trivial: just subtract one timestamp from another to get the duration in seconds.