Unix Timestamp Converter
timestampConvert Unix timestamps to dates and back. Batch convert many at once — every result stays in a list, with time zones, CSV export and code snippets.
The time zone and number unit you pick here apply to everything below.
* Unix time or a date-time — either works. One per line.
Nothing here yet
Type or paste a value above and press Enter. Every result stays in this list instead of disappearing.
// Unix -> Date
const d = new Date(1785553631 * 1000)
d.toISOString() // "2026-08-01T03:07:11.851Z"
d.toLocaleString('en-CA', { timeZone: 'Asia/Seoul', hour12: false })
// Date -> Unix
Math.floor(Date.now() / 1000) // seconds
Date.now() // millisecondsUses the row you picked with ⇄, or the top row if none is picked.
Tips
- 01Paste many lines copied straight from a log — every one is converted at once.
- 02Star ★ the values you keep coming back to; “Clear all” leaves them alone.
- 03Change the time zone or number unit and the whole list recalculates instantly.
- 04Pick ⇄ on two rows to get the exact gap between them — handy for log analysis.
- 05Type now, +1d or -3h to add a time relative to this moment.
Everything is processed in your browser. Nothing is sent to a server.
Frequently asked questions
What is the difference between a 10-digit and a 13-digit timestamp?
The number of digits tells you the unit. 10 digits are seconds, 13 are milliseconds, 16 are microseconds and 19 are nanoseconds. Reading the wrong unit throws the result off badly: a seconds value read as milliseconds lands around 21 January 1970, while a milliseconds value read as seconds lands somewhere in the year 58540. This tool detects the unit from the digit count, and you can also set it by hand at the top.
The converted time is off by several hours.
A Unix timestamp is an absolute point in time measured in coordinated universal time. The same number looks different depending on the display time zone, but the value is not wrong. Switch the zone at the top and the whole saved list is recalculated. Korean standard time, for example, runs 9 hours ahead of universal time.
How do I turn a timestamp into a date in Excel?
If the seconds value sits in A1, enter =(A1/86400)+DATE(1970,1,1) and format the cell as a date to get universal time, adding 9/24 for Korean time. To go back to seconds, use =(A1-DATE(1970,1,1))*86400. For a 13-digit millisecond value, divide by 1000 first. With many rows it is faster to convert them here and export the list as CSV.
What is the year 2038 problem?
A signed 32-bit integer holding seconds tops out at 2147483647, which is 19 January 2038 at 03:14:07 universal time. Past that moment an old 32-bit system can overflow and wrap around to a negative value. Current languages and databases mostly work with 64-bit values, so you rarely meet this in practice, and this tool is not affected.
Are the values I enter sent to a server?
No. Everything is converted inside your browser and nothing you type is sent to a server. The conversion list is stored only in this browser, so it survives a reload, and Clear all removes it. On a shared computer it is safer to empty the list before you leave.