Unix Timestamp Converter
Convert Unix epoch timestamps to human-readable dates and vice-versa (supports milliseconds).
What is the Unix Timestamp Converter?
The Unix Timestamp Converter is a free tool that converts Unix epoch timestamps into human-readable dates and converts calendar dates back into timestamps. It accepts both 10-digit second timestamps and 13-digit millisecond timestamps and detects which you entered automatically.
A Unix timestamp is the number of seconds elapsed since January 1, 1970 00:00:00 UTC. The tool shows the converted result in several formats at once, including ISO 8601, UTC string, and your local date and time, plus a breakdown of the year, month, day, and weekday.
It runs entirely in your browser with no signup, and nothing you enter is sent to a server. Conversions update live as you type.
How to use the Unix Timestamp Converter
- 1Enter a Unix timestamp in the left field; the tool detects 10-digit seconds and 13-digit milliseconds automatically.
- 2Use the Now, 1 Hour Ago, 1 Day Ago, or 1 Week Ago buttons to load a quick example timestamp.
- 3To go the other way, pick a date and time in the right-hand Date and Time field.
- 4Read the converted timestamp in seconds and milliseconds from that date.
- 5Review the Formatted Output card for ISO 8601, UTC, local, and Unix representations.
- 6Click the copy icon next to any value, or press Ctrl+L to reset both fields to the current time.
What you can use it for
- Decoding a Unix timestamp found in a database row, log line, or API response into a readable date.
- Converting a specific calendar date into a Unix timestamp for a query or API request.
- Checking whether a timestamp is in seconds or milliseconds before using it in code.
- Getting an ISO 8601 string for a given moment to store or pass between systems.
- Inspecting the year, month, day, and weekday for a timestamp during debugging.
- Generating a timestamp for a relative point in time, such as one week ago, for filtering data.
Key features
- Automatic detection of seconds (10-digit) versus milliseconds (13-digit) timestamps.
- Two-way conversion between Unix timestamps and calendar dates.
- Multiple output formats including ISO 8601, UTC string, and local date and time.
- Year, month, day, and weekday breakdown for any converted timestamp.
Frequently asked questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC, known as the Unix epoch. It is a timezone-independent way to represent a single point in time as a plain integer.
How do I convert a Unix timestamp to a date?
Paste the timestamp into the converter's timestamp field. It detects whether the value is in seconds or milliseconds and shows the date in ISO 8601, UTC, and your local format, along with a year, month, day, and weekday breakdown.
What is the difference between a 10-digit and 13-digit timestamp?
A 10-digit timestamp is measured in seconds, the standard Unix time format. A 13-digit timestamp is measured in milliseconds, which is what JavaScript's Date.now() returns. This tool detects the length and converts accordingly.
Are Unix timestamps affected by timezones?
No. A Unix timestamp always represents a moment in UTC, so the integer itself is timezone-independent. Only the human-readable date depends on a timezone, which is why this tool shows both UTC and local formats.
How do I convert a date to a Unix timestamp?
Use the Date to Unix Timestamp panel, pick a date and time, and the tool shows the equivalent timestamp in both seconds and milliseconds, ready to copy.
What is the year 2038 problem?
Systems that store Unix time in a signed 32-bit integer can only count up to January 19, 2038, after which the value overflows. Modern 64-bit systems avoid this limit. It is a storage concern in legacy code, not something that affects this converter.