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TNToolsNexus

Unix timestamp converter

Unix timestamp to date and back — seconds or milliseconds auto-detected, UTC + local + relative views, and a Now button.

Timestamp → date

Date → timestamp

Conversion happens on your device — nothing is sent anywhere.

Paste an epoch — seconds or milliseconds, auto-detected — and get UTC, your local time, and a plain-English relative reading; or pick a date and get the epoch back. A Now button for the number every debugging session eventually needs.

How to convert a timestamp

  1. Paste the number (the tool says whether it read seconds or milliseconds).
  2. Read UTC ISO, local time, relative (“in 3 days” / “5 minutes ago”), and both unit forms.
  3. Going the other way: pick a date & time, copy the epoch seconds.

The bug this page mostly debugs

Half of all timestamp confusion is the ×1000 problem: seconds where milliseconds were expected or vice versa, producing dates in 1970 or the year 56,000. Auto-detection by digit count answers it instantly — and the seconds/milliseconds line shows both forms so you can hand the right one to whatever API you’re feeding. The other half is timezone squinting, which the side-by-side UTC and local views settle without mental arithmetic.

Where epochs come from

Log lines, JWT exp/iat claims (decode those next door in the JWT decoder), database columns, API responses, cache headers, cron debugging. Turning “1783166400” into “July 4th, noon UTC — two hours ago” is the difference between reading logs and translating them. Durations between two dates are the date difference calculator’s job.

Private by design

Conversion is arithmetic on your device — nothing you paste is transmitted or kept.

Last updated:

Frequently asked questions

Seconds or milliseconds — how does it know?
By digit count: today's Unix time is 10 digits in seconds and 13 in milliseconds, so the tool reads ≤11 digits as seconds and 12–14 as milliseconds, and tells you which assumption it made. If a date looks off by ~1970 or ×1000, the source used the other unit.
What exactly is Unix time?
The count of seconds since 1970-01-01T00:00:00 UTC (the epoch), ignoring leap seconds. It's timezone-free by definition — the same instant everywhere — which is why systems store it and humans need converters.
Why do UTC and my local time differ?
They're the same instant in two zones: UTC is the timestamp's native reading; the local line applies your device's timezone (including DST). When filing bug reports, quote the UTC ISO line — it's unambiguous.
Does the date → timestamp direction use my timezone?
Yes — the picker reads as your local wall-clock time and converts to the universal epoch value, which is what you want when translating "it happened at 3pm my time" into a log query.
Negative timestamps?
Valid — they count backwards from 1970. -86400 is 1969-12-31. Handy for historical data; also the telltale of an underflow bug.

Related tools

JWT Decoder

Decode a JWT's header and payload, humanize exp/iat/nbf with an expired verdict — locally, with the decode-is-not-verify warning up front.

Date Difference Calculator

Count the days between two dates — total days, weeks plus days, and a calendar breakdown, with an option to include the end day.

Age Calculator

Turn a date of birth into an exact age in years, months, and days — plus total days lived and a countdown to the next birthday.