A Unix timestamp, or epoch time, is the number of seconds since 1 January 1970 00:00:00 UTC. 1700000000, for example, is 14 November 2023 22:13:20 UTC. It names the same instant everywhere on Earth, which is why logs, APIs and databases use it.
Seconds, milliseconds, microseconds or nanoseconds?
Count the digits. Present-day timestamps have 10 digits in seconds (1700000000), 13 in milliseconds (1700000000000), 16 in microseconds (1700000000000000) and 19 in nanoseconds (1700000000000000000). The tool detects the unit this way, and you can override it.
JavaScript's Date.now() returns milliseconds, while Unix tools, PHP and many APIs and databases use seconds. Mixing them up is why a date lands in 1970 or thousands of years from now.
Time zones and daylight saving
A timestamp has no time zone; the zone only changes how it is displayed. 1700000000 is 22:13 in London and 17:13 in New York. Going from a wall-clock time to a timestamp does need a zone, and daylight saving can make a local time happen twice or not at all. The tool says when that happens and which instant it chose.
The Year 2038 problem
Software that stores Unix time in a signed 32-bit integer (time_t) can count only to 2147483647, which is 19 January 2038 03:14:07 UTC. One second later the value overflows to a negative number that reads as December 1901. Most systems now use 64-bit time; embedded devices and 32-bit database columns are worth checking.
Leap seconds
Unix time ignores leap seconds: every day counts as exactly 86,400 seconds, and when a leap second is inserted the Unix clock repeats a second instead of counting it.
How to use
- Timestamp to date: paste a timestamp; the unit is detected from its length, or choose it.
- Date to timestamp: fill in the fields, pick a date, or paste an ISO 8601 date, then choose the time zone it belongs to.
- Batch: paste up to 5,000 timestamps, one per line, then copy the table or download it as CSV.
Features
- Seconds to nanoseconds, detected automatically, with every digit of long values kept.
- Negative timestamps for dates before 1970, and decimal seconds such as 1700000000.123.
- UTC, local and any IANA time zone, ISO 8601, RFC 2822, ISO week and relative time.
- Warnings for times skipped or repeated by daylight saving, and CSV that spreadsheets won't run as formulas.
Common uses
- Debugging API responses and logs. Turn created_at fields and log lines into readable dates.
- Checking JWTs. The exp, iat and nbf claims of a JSON Web Token are Unix seconds: see when a token was issued and when it expires.
- Database fields. Read integer time columns, or work out the value to use in a query.
- Cron and scheduled jobs. Check when a job ran or will run, in the server's time zone.
- Preparing test data for QA. Generate timestamps around daylight saving changes, year boundaries and 2038 to test edge cases.
Frequently asked questions
What is epoch time?
Another name for Unix time: the seconds since the Unix epoch, 1 January 1970 00:00:00 UTC. 0 is that moment and 86400 is exactly one day later.
How do I convert a timestamp to a date?
Paste it into Timestamp to date above. In JavaScript, multiply seconds by 1000: new Date(1700000000 * 1000). In Python, use datetime.fromtimestamp(1700000000, timezone.utc).
How do I get the current timestamp?
JavaScript: Math.floor(Date.now() / 1000). Python: int(time.time()). Shell: date +%s. PHP: time(). Java: Instant.now().getEpochSecond(). The clock at the top of this page shows it too.
Is a timestamp in seconds or milliseconds?
Count the digits: a present-day date has 10 in seconds and 13 in milliseconds. A result in January 1970 means seconds were read as milliseconds; a year in the tens of thousands means the opposite.
What is the Year 2038 problem?
A signed 32-bit time_t overflows after 19 January 2038 03:14:07 UTC. Software with 64-bit time is unaffected; old or embedded code needs checking.
Why does my date show the wrong day?
Usually a time zone. 1700000000 is 22:13 on 14 November in UTC but already 03:43 on 15 November in India (UTC+05:30). Check which zone your code formats dates in.
Can timestamps be negative?
Yes. Negative values count back from 1970: -86400 is 31 December 1969 00:00:00 UTC. Some languages and databases reject them, so test older dates such as birth dates.
Is my data uploaded?
No. Every conversion runs in your browser, and what you type is never sent to a server or saved. Like the rest of the site, the page records a visit when it loads, but not your input.
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