Epoch / Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back, with timezone support.
Current Unix Timestamp
seconds since Jan 1, 1970 00:00:00 UTC
→ Timestamp to Date
→ Date to Timestamp
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, 00:00:00 UTC — a moment known as the “Unix Epoch.” This system was introduced with Unix operating systems and has since become the universal standard for representing points in time in computing.
Unix timestamps are timezone-agnostic: the value 1700000000 represents the exact same moment worldwide, regardless of the observer’s timezone. This makes them ideal for databases, APIs, log files, and distributed systems where timezone ambiguity could cause bugs. Most programming languages, databases, and operating systems provide native support for Unix timestamps.
A common variation is the millisecond timestamp, which counts milliseconds since the Epoch (13 digits instead of 10). JavaScript’s Date.now() returns millisecond timestamps, while most server-side languages default to seconds. Our converter automatically detects whether your input is in seconds or milliseconds.
How to Use This Converter
- Live Epoch Counter — The large counter at the top shows the current Unix timestamp, updating every second. Click “Copy” to grab it.
- Timestamp → Date — Paste a Unix timestamp (seconds or milliseconds) and click Convert to see the human-readable date in your selected timezone.
- Date → Timestamp — Select a date and time using the datetime picker and convert it to a Unix timestamp.
- Timezone Selector — Choose from 8 common timezones including UTC, Berlin, New York, Tokyo, and more.
Frequently Asked Questions
What is the Year 2038 problem?
Systems storing Unix timestamps as 32-bit signed integers will overflow on January 19, 2038 at 03:14:07 UTC. After this point, the timestamp wraps to a negative number causing incorrect dates. Modern 64-bit systems using int64 timestamps are safe until the year 292,277,026,596 CE. Check any legacy embedded systems or 32-bit databases in your infrastructure.
What's the difference between seconds and milliseconds timestamps?
A seconds timestamp has 10 digits (e.g., 1700000000), while a milliseconds timestamp has 13 digits (e.g., 1700000000000). JavaScript's Date.now() uses milliseconds. Most Unix utilities, Linux time(), and databases like PostgreSQL use seconds. Our tool auto-detects whether your input is seconds or milliseconds based on the digit count.
Why do timestamps always reference UTC?
UTC (Coordinated Universal Time) provides a single, unambiguous reference point across all geographies. By storing times as UTC and converting to local timezones only at display time, systems avoid daylight saving time (DST) transition bugs, timezone rule changes, and ambiguous local times during DST changeovers.
Can timestamps represent dates before 1970?
Yes. Negative Unix timestamps represent dates before the Unix Epoch (January 1, 1970 00:00:00 UTC). For example, -86400 represents December 31, 1969 at 23:59:59 UTC. Most modern timestamp libraries handle negative timestamps correctly, though some legacy systems may not.
What is the difference between Unix time and ISO 8601?
Unix time is an integer count of seconds since 1970-01-01T00:00:00Z. ISO 8601 is a human-readable date/time string format like '2025-04-15T14:30:00+02:00'. ISO 8601 includes timezone information explicitly; Unix time is always UTC. XML files (including XRechnung) use ISO 8601 date strings, not Unix timestamps.
How does Daylight Saving Time (DST) affect timestamps?
It doesn't — Unix timestamps are always UTC and have no concept of DST. DST only matters when converting a timestamp to a local time for display. For example, the same Unix timestamp displays as 14:00 CET in winter and 15:00 CEST in summer in Berlin. This is why storing and transmitting timestamps in UTC is the recommended practice.
What timestamp format does XRechnung use?
XRechnung uses ISO 8601 date strings in the format YYYY-MM-DD (e.g., 2025-04-15) for invoice dates, delivery dates, and payment due dates. It does not use Unix timestamps. If you need to convert between Unix timestamps and XRechnung date strings, our converter handles this conversion in both directions.
How precise is a Unix timestamp?
A standard Unix timestamp in seconds has 1-second precision. Millisecond timestamps (used in JavaScript and many modern APIs) have 1-millisecond precision. For sub-millisecond precision (network packets, financial transactions), systems use nanosecond timestamps, though these are not standard Unix timestamps.
Can I store timestamps in a database?
Yes. Use the database's native timestamp type (TIMESTAMP WITH TIME ZONE in PostgreSQL, DATETIME in MySQL) rather than storing raw integers. Native timestamp types handle timezone conversion, DST awareness, and comparison operations correctly. For cross-database compatibility, storing UTC Unix timestamps in a BIGINT column is also a reliable pattern.