You’re reading a server log, an API response or a database row, and the time is shown as a number like 1789000000 — or a 13-digit one like 1789000000000. That’s a Unix timestamp, and it isn’t something you can read at a glance.
This guide shows you how to convert a Unix timestamp to a readable date, and a date back to a timestamp, with the free Unix Timestamp Converter.
Every time I dug through logs, I ended up searching “what date is this number?”. So I built a tool where you paste the number and see your local time and UTC side by side.
What is a Unix timestamp?
A Unix timestamp (also called epoch time) counts the seconds that have passed since 00:00:00 UTC on January 1, 1970. For example, 1789000000 is September 10, 2026, 00:26:40 UTC.
Because it’s just a number — no time zones, no date formats — it’s an easy way for computers to exchange times. That’s why you’ll find it in logs, databases and APIs everywhere. The downside is that people can’t read it.
Some systems count milliseconds instead of seconds. Those timestamps have three more digits, so they’re 13 digits long.
What this tool does
- Converts a Unix timestamp to a date in your local time and in UTC
- Detects seconds (10 digits) or milliseconds (13 digits) automatically
- Converts a date and time you pick into a timestamp in seconds and milliseconds
- Fills in the current time with one click
- Copies the result in seconds or milliseconds with one click
How to use it
Step 1. Open the tool
Open the Unix Timestamp Converter. There’s nothing to install and no sign-up.
Step 2. Convert a timestamp to a date
Paste the number from your log into the Timestamp → date field. You’ll see the date in your local time and in UTC, along with whether it was read as seconds or milliseconds.
10 digits are read as seconds, 13 as milliseconds
Step 3. Convert a date to a timestamp
To go the other way, pick a date and time under Date (your local time) → timestamp. You’ll get the value in both seconds and milliseconds; use Copy seconds or Copy milliseconds to grab the one you need.
Step 4. Check the current time
Click Use current time to fill in the timestamp for right now. It’s handy for creating test data or comparing a log entry with the current time.
When a log time looks hours off, the usual culprit is reading a UTC time as if it were local time. Seeing both side by side makes that mistake easy to spot.
When this comes in handy
- Debugging from logs: find out exactly when an error happened
- API development and testing: check dates in responses, or create values for requests
- Database checks: make created-at and updated-at columns readable
- Expiry times: see when a token or signed URL actually expires
FAQ
How do I convert a Unix timestamp in Excel or Google Sheets?
If cell A1 holds a timestamp in seconds, use this formula and format the cell as a date and time:
=A1/86400+25569
86400 is the number of seconds in a day, and 25569 is Excel’s serial number for January 1, 1970. The result is in UTC; to show your local time, add your offset in days — for example, -5/24 for UTC−5. For a millisecond timestamp, divide A1 by 1000 first. To learn more about Excel’s serial numbers, see How to Convert Excel Serial Numbers (Like 45292) to Dates.
How do I get the current Unix time in code?
It depends on the language, and some return seconds while others return milliseconds. JavaScript’s Date.now() returns milliseconds, Python’s time.time() returns seconds (with decimals), and PHP’s time() returns seconds. Check the unit before you use it.
Does a Unix timestamp have a time zone?
No. A Unix timestamp is the same worldwide for the same moment — it’s identical in New York and Tokyo. Time zones only matter when you turn it into a clock time for display.
Things to watch out for
- Microseconds and nanoseconds aren’t supported: for 16-digit (microsecond) or 19-digit (nanosecond) values, drop the extra digits to get 13 (milliseconds) or 10 (seconds)
- Dates you enter use your device’s time zone: to convert a UTC time, enter it adjusted to your local time, or check the UTC line in the result
- Leap seconds aren’t counted: Unix time ignores leap seconds by design. This doesn’t matter for everyday use
Summary
Those 10- and 13-digit numbers in logs and APIs are Unix timestamps — time counted from 1970. Paste one in and you’ll see the date in your local time and UTC, which makes log digging and API checks much quicker.
Try pasting a timestamp from your own logs and see when it was recorded.
