Unix Timestamps Explained - What They Are and How to Use Them
Learn what Unix timestamps are, how they work, and why they are the standard for storing time in software systems.
What Is a Unix Timestamp?
A Unix timestamp (also called Epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC. This date is known as the Unix Epoch. For example, the timestamp 1700000000 represents November 14, 2023, at 22:13:20 UTC.
Why Unix Timestamps Are Used
- Timezone independent — A Unix timestamp represents an absolute point in time regardless of timezone. No ambiguity about DST or UTC offsets.
- Easy to compare — Comparing two timestamps is a simple integer comparison. Is event A before event B? Just check if
timestampA < timestampB. - Compact storage — A single 32-bit or 64-bit integer is far more efficient than storing date strings.
- Language agnostic — Every programming language can work with Unix timestamps natively.
Converting Timestamps
In JavaScript: new Date(timestamp * 1000) converts a Unix timestamp to a Date object (JavaScript uses milliseconds). In Python: datetime.fromtimestamp(timestamp). In SQL: FROM_UNIXTIME(timestamp) for MySQL or to_timestamp(timestamp) for PostgreSQL.
The Year 2038 Problem
32-bit systems store Unix time as a signed integer, which overflows on January 19, 2038, at 03:14:07 UTC. This is similar to the Y2K bug. Modern systems use 64-bit integers, which can represent dates for billions of years into the future.
Convert Timestamps Instantly
Use our Unix Timestamp Converter to convert between Unix timestamps and human-readable dates. Enter a timestamp to see the date, or enter a date to get its timestamp. The tool supports both seconds and milliseconds.
Current Unix Timestamp
The current Unix timestamp changes every second. Our converter shows the current timestamp in real time, making it handy for developers who need to generate timestamps for API calls, database entries, or logging.