What is a Unix Timestamp?
A Unix timestamp (also known as Epoch time, POSIX time, or Unix Epoch time) represents the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC — a moment known as the Unix Epoch. This deceptively simple integer is one of the most fundamental concepts in computing and is used across virtually every programming language, database, and operating system.
For example, the timestamp 1710500000 corresponds to Fri Mar 15 2024 10:13:20 UTC. Because Unix timestamps are timezone-independent integers, they eliminate ambiguity in time representation across distributed systems.
How to Use This Converter
Enter a Unix timestamp (seconds or milliseconds) and click Convert to see the human-readable date in UTC, local time, and ISO 8601 format.
Pick a date and time using the input fields and click Convert to get the corresponding Unix timestamp in both seconds and milliseconds.
The current Unix timestamp updates every second at the top of the tool. Click Copy to grab it instantly.
Where Are Unix Timestamps Used?
Developers encounter Unix timestamps constantly across the software stack:
- APIs and Web Services: REST and GraphQL APIs often return timestamps as integers for dates like
created_atandupdated_atfields. - Databases: PostgreSQL, MySQL, MongoDB, and Redis store dates as epoch values for efficient indexing and comparison.
- Server Logs: System logs, access logs, and application logs frequently use Unix timestamps for sorting and querying.
- JWT Tokens: JSON Web Tokens use Unix timestamps for
iat(issued at),exp(expiration), andnbf(not before) claims. - Cron Jobs: Scheduled tasks and cron expressions are resolved against epoch time.
- File Systems: File creation and modification times are stored as epoch values on Unix/Linux and macOS systems.
Seconds vs Milliseconds
The standard Unix timestamp is measured in seconds and produces a 10-digit number (as of 2024). However, many modern systems use milliseconds for greater precision, producing a 13-digit number.
Seconds (10 digits)
- Standard Unix/POSIX format
- Used by PHP, Python, Ruby, C
- Example:
1710500000 - Most APIs and databases
Milliseconds (13 digits)
- JavaScript
Date.now() - Java
System.currentTimeMillis() - Example:
1710500000000 - Sub-second precision
Notable Epoch Timestamps
| Timestamp | Date (UTC) | Significance |
|---|---|---|
| 0 | Jan 1, 1970 00:00:00 | The Unix Epoch |
| 1000000000 | Sep 9, 2001 01:46:40 | Billennium (1 billion seconds) |
| 1234567890 | Feb 13, 2009 23:31:30 | Sequential digits celebration |
| 2000000000 | May 18, 2033 03:33:20 | 2 billion seconds |
| 2147483647 | Jan 19, 2038 03:14:07 | Year 2038 problem (32-bit overflow) |
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, at 00:00:00 UTC. It is a widely used format for representing time in computing because it is timezone-independent and easy to compute with.
What is the difference between seconds and milliseconds timestamps?
A standard Unix timestamp is in seconds (10 digits, e.g. 1710500000). Some systems like JavaScript's Date.now() use milliseconds (13 digits, e.g. 1710500000000). This tool auto-detects the format, or you can choose manually.
Is this tool accurate for all dates?
Yes. This tool uses the JavaScript Date API which supports dates from approximately 271,821 BCE to 275,760 CE. All conversions happen locally in your browser with no server calls.
Why do developers use Unix timestamps?
Unix timestamps are timezone-independent, making them ideal for storing dates in databases, APIs, and logs. They are simple integers which makes them easy to compare, sort, and calculate time differences without dealing with complex date formatting.
What happens at the Year 2038 problem?
On January 19, 2038, 32-bit signed integers overflow for Unix timestamps. This tool uses JavaScript which stores timestamps as 64-bit floating-point numbers, so it is not affected. However, systems using 32-bit integers will need to be updated.
Is my data safe with this tool?
Yes. All conversions happen entirely in your browser. No timestamps or dates are ever sent to our servers, ensuring complete privacy.