Unix Timestamp Converter

What you can do

• Convert a Unix timestamp to a readable date in local time, UTC or any timezone.
• Convert seconds, milliseconds, microseconds and nanoseconds, detected automatically from the number of digits.
• Turn a date into a Unix timestamp, typed as ISO 8601 or RFC 2822 or picked with date and time fields.
• Copy the current Unix timestamp in seconds or milliseconds.
• Compare one moment across several timezones side by side.
• Decode negative timestamps for dates before 1970.
• See the day of week, day of year and ISO week of a timestamp.
• Check how far your device's clock drifts from the server.

How to use the Unix Timestamp Converter

1. 1Paste a timestamp, or press Now to load the current one.
2. 2Check the detected unit, and override it with the unit picker if the guess is wrong.
3. 3Read the converted date rows, and copy the format you need.
4. 4For the reverse direction, type a date or pick one with the fields, choose a timezone, and copy the timestamp in the unit you want.

How the unit detection works

A Unix timestamp counts time since January 1, 1970 UTC, but different systems count in different units. The same moment in late 2023 is 1700000000 in seconds, 1700000000000 in milliseconds and 1700000000000000000 in nanoseconds. The tool guesses from the number of digits: up to 11 digits reads as seconds, 12 to 14 as milliseconds, 15 to 17 as microseconds and anything longer as nanoseconds. That covers every plausible modern value, and the picker under the input lets you force a unit when you know better.

Nanosecond timestamps are longer than JavaScript numbers can hold exactly, so the math runs on exact integers throughout. Fractions work too: 1700000000.25 seconds converts down to the nanosecond.

Dates without a timezone are ambiguous

A string like 2024-02-29 13:45 names a wall clock reading, not a moment: it happens at a different instant in Berlin than in New York. When your input carries no offset, the tool interprets it in the timezone you picked and says so under the input. An explicit offset like +02:00 or a trailing Z always wins. The word now also works as an input.

Daylight saving time creates two odd cases the tool calls out: a wall time that never happens when clocks jump forward, and one that happens twice when they fall back.

About the server time check

The server clock comes from the HTTP Date header of a quick request to this site. That header only carries whole seconds and the network adds travel time, so the comparison is accurate to about a second at best. It is still enough to spot a device clock that is minutes off, a common cause of failing TOTP codes and expired-token errors.