Unix Timestamp Converter
Switch between Unix → Date and Date → Unix to read epoch seconds or milliseconds as dates or get the timestamp for any date.
Runs in your browser. Nothing you enter is uploaded.
What it does
Paste an epoch value such as 1700000000 and the converter shows the same moment three ways: ISO 8601, your browser's local time, and UTC. Flip to Date → Unix and it does the reverse, returning both epoch seconds and epoch milliseconds for a date you type.
It is built for the moments when a log line, a JSON field like created_at, or a database row gives you a 10-digit or 13-digit number and you need to know what day and hour it means, or when you need a timestamp to paste into a query or API call.
How to use it
- 1
Choose Unix → Date or Date → Unix with the buttons at the top.
- 2
Type into the input: epoch seconds or milliseconds for Unix → Date, or a date string or ISO date for Date → Unix.
- 3
Read the Converted box, which updates as you type.
- 4
Click Use current time if you want the present moment as a starting value.
- 5
Click Copy result to copy every line of the converted output.
What you get
Unix → Date returns three lines (ISO, Local, UTC) and a note saying whether the input was read as seconds or milliseconds. Date → Unix returns two lines: Unix (seconds) and Unix (ms). Invalid input shows "Invalid timestamp" or "Invalid date".
When to use it
- Read timestamps in API responses
- Copy an epoch field from a JSON payload into Unix → Date to see the ISO and UTC time without writing code.
- Build a date filter for queries
- Type a date like 2024-01-01T00:00:00Z in Date → Unix and paste the seconds value into a SQL WHERE clause or API parameter.
- Check scheduled post times
- Compare the Local and UTC lines to confirm a timestamp lands at the hour you expected in your own time zone.
- Grab the current epoch
- Click Use current time to fill in the current Unix time in seconds.
Example
Input
1700000000 (Unix → Date)
Output
ISO: 2023-11-14T22:13:20.000Z Local: depends on your browser time zone UTC: Tue, 14 Nov 2023 22:13:20 GMT
Going the other way, 2024-01-01T00:00:00Z returns Unix (seconds): 1704067200 and Unix (ms): 1704067200000.
Tips
- You can paste a millisecond value straight from JavaScript Date.now(). Any value of 1,000,000,000,000 or more is read as milliseconds, and the note above the result confirms which unit was used.
- In Date → Unix, add Z or an offset like +05:00 to the date string. "2024-01-01T09:00" without one is read in your browser's local time zone, while a date-only value like "2024-01-01" is read as midnight UTC.
- Decimal input is cut at the decimal point, so 1700000000.75 converts as 1700000000.
- The Local line uses your device settings, so a teammate in another time zone will see a different Local value for the same timestamp. Share the ISO or UTC line instead.
Questions
How do I tell if a timestamp is in seconds or milliseconds?
Current Unix times in seconds have 10 digits (for example 1700000000). Milliseconds have 13 digits (1700000000000). This converter checks the size for you: values of 1,000,000,000,000 or more are treated as milliseconds, and a note shows the detected unit.
Why is the Local time different from the UTC time?
A Unix timestamp is a single moment. The Local line formats it in your browser's time zone, while UTC shows it at zero offset. Both describe the same instant.
What date formats does Date → Unix accept?
Anything your browser's Date parser understands. ISO 8601 strings such as 2024-03-15T14:30:00Z are the most reliable across browsers; free-form strings like "March 15 2024" usually work but can vary.
Can I convert a negative timestamp for dates before 1970?
Yes. parseInt accepts a leading minus sign, so -86400 converts to 31 December 1969. Date → Unix also returns negative values for dates before 1970.