What is a Unix Timestamp?
Unix time (also referred to as Epoch time or POSIX time) is a widely adopted system for tracking points in time. It defines a moment by measuring the total number of seconds elapsed since the “Unix Epoch”—which occurred on January 1, 1970, at 00:00:00 UTC (Coordinated Universal Time). The count continues incrementing, ignoring leap seconds.
Because databases, APIs, and servers store dates as single integer values (e.g., 1781212800), developers frequently encounter timestamps in logs, metrics, and payload responses. Since these integers are unreadable to humans, a conversion tool is necessary to translate between numeric values and calendar dates.
By using our Unix Timestamp Converter, you can instantly translate epoch timestamps to formatted, human-readable date-times, and convert standard dates back to Unix integers.
Seconds vs. Milliseconds
One of the most common developer mistakes when handling time is confusing seconds with milliseconds:
- Seconds: The traditional Unix timestamp, which is 10 digits long (e.g.,
1781212800). This is standard in Unix/Linux command-line tools, databases like PostgreSQL (when storing epoch), and backend languages like Python or PHP. - Milliseconds: A 13-digit integer (e.g.,
1781212800000). This is the default format used in JavaScript (viaDate.now()), Java, and many modern web API payloads.
Passing a second-based timestamp into a system expecting milliseconds results in dates from 1970, while the reverse causes date overflow errors. Our tool automatically detects the input format (10-digit or 13-digit) to prevent these bugs.
Real-World Developer Use Cases
- Debugging API Payloads: Quickly identifying when a record was created or modified by parsing the numeric timestamps returned in a JSON response.
- Log Verification: Translating server crash times or error logs from epoch format to local timezone times for easier troubleshooting.
- Database Query Building: Calculating the correct integer representation of a date to write precise SQL queries like
WHERE created_at > 1781212800.
How to Convert Unix Timestamps
- Convert Timestamp to Date: Open the Unix Timestamp Converter page. Paste your 10-digit or 13-digit integer into the Timestamp Input field. The tool will instantly display the date and time in both UTC and your local timezone.
- Convert Date to Timestamp: Use the interactive calendar date-picker to select a specific date, hour, minute, and second. The corresponding Unix timestamp (both in seconds and milliseconds) will update instantly.
- Use the Live Clock: Refer to the live ticking clock at the top of the interface to check the current Unix time and copy it with a single click.