Convert between Unix timestamps and readable dates
Timestamps come out of logs, APIs and databases in whatever unit the system felt like using, and they always need to be read in a specific timezone. This converter handles the unit and the timezone explicitly.
- Units
- s, ms, µs, ns
- Zones
- UTC and local
- Direction
- Both ways
| Representation | Value |
|---|
How to use it
- Paste a timestamp or a date A number is read as a Unix timestamp in the unit you select. A date string is parsed and converted the other way.
- Pick the unit Seconds, milliseconds, microseconds and nanoseconds are all common in the wild, and getting the unit wrong produces a date in the year 2000 or the year 55000.
- Read it in both zones The result is shown in UTC and in your local timezone, along with the ISO 8601 form, the RFC 3339 form and the relative offset.
Questions people ask
How do I know if a timestamp is in seconds or milliseconds?
By its magnitude. A seconds timestamp for a date around 2026 is a ten-digit number near 1,767,000,000. The same moment in milliseconds is thirteen digits near 1,767,000,000,000. If the number has more than 11 digits, it is almost certainly milliseconds.
What is the Unix epoch?
1 January 1970 at 00:00:00 UTC. A Unix timestamp is the number of seconds since that moment. Timestamps before it are negative.
Does the converter handle leap years and DST?
Yes. Dates are computed with the full calendar rules for the relevant year. Daylight saving transitions are applied according to your local timezone, so a time that falls inside a DST jump is shown correctly.
What is the ISO 8601 format exactly?
A calendar date in the year-month-day form, followed by a T and a 24-hour time in hour:minute:second, with an optional fractional part and a Z or numeric offset for the timezone. The Z suffix means UTC.
Why does my date come out 45 years in the future?
A seconds timestamp was passed to a function expecting milliseconds. Multiply a seconds value by 1,000 to get milliseconds, and by 1,000,000 for microseconds.
Can I convert a date in a specific timezone?
Yes. Choose UTC, your local zone, or enter a fixed offset such as +05:30, and the result is converted into it.
Reference
The same moment in different representations
| Representation | Value |
|---|---|
| Unix seconds | `1767225600` |
| Unix milliseconds | `1767225600000` |
| ISO 8601 (UTC) | `2026-01-01T00:00:00.000Z` |
| RFC 3339 | `2026-01-01T00:00:00Z` |
| SQL format | `2026-01-01 00:00:00` |
Details that catch people out
Unix time counts seconds since 1970-01-01 UTC and does not account for leap seconds, so it drifts slightly from UTC. For anything requiring legally defined time, use UTC with an explicit leap-second table.
A 32-bit signed integer overflows in 2038. A value of 2,147,483,647 is the last second that fits, which is why you should use a 64-bit field for any timestamp you store.
Where this earns its keep
Reading a log line
A raw epoch in a log becomes a human date, with the timezone spelled out, in a single paste.
Debugging a date bug
When a date shows up 1,000 times too large, the system is mixing milliseconds and seconds. Seeing both units side by side makes the mismatch obvious.
Preparing an API parameter
Most payment and scheduling APIs want a Unix timestamp in seconds, and the most common cause of a rejected request is the wrong unit.
Guides that go deeper
- UTC vs Local Time: The Bugs It Causes 6 min read · Why storing local time is a bug waiting to happen, how daylight saving breaks naive date…
- Cron Expressions: A Cheat Sheet and Its Traps 7 min read · The five fields of a Unix cron expression, the day-of-month and day-of-week rule that…
Last reviewed 2026-10-12. Every tool on DevSnap runs entirely in your browser, so whatever you paste here never reaches a server.