Last updated: March 2026
What Is a Unix Timestamp?
A Unix timestamp, also known as epoch time or POSIX time, represents the number of seconds that have elapsed since the Unix epoch — January 1, 1970, at 00:00:00 Coordinated Universal Time (UTC). This deceptively simple concept is one of the most important standards in computing. Every major programming language, database system, and operating system uses Unix timestamps internally to track and compare times. Because timestamps are just numbers, they are timezone-independent, easy to sort, and trivial to use in calculations like finding the difference between two events. This converter lets you instantly translate between raw timestamps and human-readable dates in any direction.
How to Convert Timestamps and Dates
To convert a Unix timestamp to a date, paste or type the timestamp into the Timestamp to Date section. The tool automatically detects whether you entered seconds (10 digits) or milliseconds (13 digits) and instantly displays the result in multiple formats: ISO 8601, RFC 2822, a human-readable format, and relative time like “2 hours ago.” You can view the result in UTC, your local timezone, or any major timezone using the dropdown. To go the other direction, use the Date to Timestamp section: pick a date, set the time, choose your timezone, and get both seconds and milliseconds timestamps with one-click copy buttons. For batch operations, the Bulk Converter accepts multiple timestamps separated by newlines and converts them all at once into a sortable, exportable table.
Why Developers Use Unix Timestamps
Unix timestamps solve a fundamental problem in software: representing time unambiguously across systems, timezones, and locales. When a database in Tokyo, an API server in London, and a frontend in New York all need to agree on when something happened, a single integer like 1710288000 removes all ambiguity. Timestamps are also compact, sortable, and fast to compare — checking whether event A happened before event B is a simple numeric comparison. They appear in server logs, JWT tokens, API responses, database records, cron jobs, and virtually every piece of infrastructure that touches time. Understanding how to read and convert timestamps is an essential skill for any developer working with APIs, debugging production issues, or analyzing log files.
Common Timestamp Formats and Standards
While Unix timestamps in seconds are the original standard, many modern platforms use milliseconds for greater precision. JavaScript's Date.now() returns milliseconds, as do Java's System.currentTimeMillis() and many REST APIs. Some systems use microseconds (16 digits) or nanoseconds (19 digits). ISO 8601 is the most widely adopted human-readable format (2024-03-13T12:00:00Z), while RFC 2822 is common in email headers and HTTP responses. This tool displays all major formats simultaneously so you never have to guess which one your system expects. The quick reference table at the bottom provides commonly needed timestamps like the start of today, this week, this month, and this year for fast lookups during development.
Frequently Asked Questions
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. It is a widely used standard for tracking time in computing, databases, APIs, and log files because it is timezone-independent and easy to compare mathematically.
What is the difference between seconds and milliseconds timestamps?
A Unix timestamp in seconds is a 10-digit number (e.g., 1710288000), while a milliseconds timestamp is 13 digits (e.g., 1710288000000). Seconds-based timestamps are the original Unix standard, while milliseconds timestamps are common in JavaScript (Date.now()), Java, and many modern APIs. This tool auto-detects which format you enter.
How does this tool handle timezones?
All Unix timestamps are inherently UTC. When converting a timestamp to a date, this tool shows both UTC and your local timezone by default, and you can select any major timezone from the dropdown to see the equivalent time. When converting a date to a timestamp, you specify which timezone the date is in so the correct UTC epoch value is calculated.
Can I convert multiple timestamps at once?
Yes. Use the Bulk Converter section to paste multiple timestamps (one per line) and convert them all at once. The results are displayed in a table with the original timestamp, human-readable date, and relative time. You can export the results as CSV or JSON.
What is the maximum Unix timestamp value?
The maximum value depends on the system. 32-bit systems can represent timestamps up to 2,147,483,647 (January 19, 2038, 03:14:07 UTC), known as the Year 2038 problem. 64-bit systems support timestamps far into the future. This tool handles any reasonable timestamp value, including negative timestamps for dates before 1970.