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Output
Enter a value to see the conversion...
Settings
Most Unix systems and APIs use seconds (10 digits, e.g. 1700000000).
All conversions are performed locally in your browser. Dates use your system timezone for local format output.
Unix Timestamp Converter
DataConvert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds, ISO 8601, UTC, local time, and relative formats.
What is a Unix timestamp?
A Unix timestamp (also called Epoch time or POSIX time) counts the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC — a moment known as the Unix Epoch. For example, the timestamp 1700000000 represents November 14, 2023. This format is used by virtually every programming language, database, and operating system because it is timezone-independent, easy to store as a single integer, trivial to sort and compare, and compact. JavaScript's Date.now() returns milliseconds since the epoch, while most Unix systems and APIs use seconds.
When developers need timestamp conversion
Developers encounter Unix timestamps constantly: API responses contain created_at fields as epoch seconds, database columns store timestamps as integers, log files use epoch time for precision, JWT tokens have exp and iat claims as timestamps, and cron jobs schedule tasks in Unix time. Quickly converting between a raw number like 1700000000 and a human-readable date like "November 14, 2023 10:13 AM" is one of the most common developer micro-tasks. This tool provides instant, bidirectional conversion with multiple output formats.
Seconds vs milliseconds and the Y2038 problem
Some systems use seconds (10-digit timestamps like 1700000000) while others use milliseconds (13-digit timestamps like 1700000000000). JavaScript, Java, and some APIs use milliseconds; Unix, Python, PHP, and most databases use seconds. This tool supports both. The Y2038 problem occurs when 32-bit signed integers overflow on January 19, 2038 at 03:14:07 UTC (timestamp 2147483647). Most modern systems have migrated to 64-bit timestamps, but legacy systems may still be affected. The quick reference section lets you jump to this and other notable timestamps.
Frequently Asked Questions
Is this timestamp converter free?
Yes, completely free with no sign-up required. All conversions happen in your browser — no data is sent to any server.
How do I know if my timestamp is in seconds or milliseconds?
Count the digits: 10-digit numbers are typically seconds (Unix standard), while 13-digit numbers are milliseconds (JavaScript, Java). For example, 1700000000 is seconds and 1700000000000 is milliseconds. Use the toggle to switch between the two.
What timezone does the converter use?
The tool shows both UTC and your local timezone. The "Local" output uses your browser's timezone setting. ISO 8601 output always includes the timezone offset. The "Relative" format shows how far the date is from right now (e.g., "3 days ago").
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