OmniTools

Unix Timestamp Converter

Epoch to date and back, in seconds, milliseconds, microseconds or nanoseconds.

Basis: Unix time (from 1970-01-01T00:00:00Z) converted both ways. The unit follows the digit count: under 12 digits seconds, under 15 milliseconds, under 18 microseconds, beyond that nanoseconds. Values past 2038-01-19 are flagged as overflowing a 32-bit seconds field·2026-09-13 verified·Editorial policy

Before you rely on this

The unit is guessed from the digit count, so very small values near 1970 and fractional values can be read the other way — pick the unit by hand in that case. Converting a date to a timestamp uses your browser time zone and that date’s daylight-saving rule. Leap seconds are not counted, because Unix time itself does not count them.

Tool Overview & Key Purpose

Converts between Unix timestamps and dates in seconds, milliseconds, microseconds and nanoseconds, guessing the scale from the digit count and showing it back to you — because getting the scale wrong lands you silently in the wrong century.

Step-by-Step Usage Instructions

1STEP 1

Pick the direction: timestamp to date, or date to timestamp.

2STEP 2

Paste the number. The unit is detected automatically, and the chips let you set it by hand.

3STEP 3

Local time, UTC, ISO 8601 and a relative phrase all appear at once, each with its own copy button.

4STEP 4

In the other direction, entering a date and time gives the timestamp in all four units.

Real-World Scenarios & Practical Cases

3 Practical CasesScenario #1

Reading a number out of a log

A Go service logs something like 1755388800000000000 — nineteen digits, so nanoseconds. Read as seconds it would land in the year 55000.

Half the job here is recognising the scale: ten digits is seconds, thirteen is milliseconds.Scenario #2

Checking an expiry

The exp claim in a JWT is a timestamp in seconds. Pasting it gives a relative phrase such as "in 3 hours" alongside the date, so you can see when the token dies.

The relative phrase is measured against your browser clock, so a skewed clock skews it too.Scenario #3

Building test data

When you need the timestamp for a particular moment, use the date-to-timestamp direction. Entering a time on a daylight-saving boundary is a quick way to check how that case is handled.

The time you type is read in your browser time zone; for a UTC-based value, read the ISO (UTC) line.Unit detection and conversion rules

Unix time counts from 1970-01-01T00:00:00Z.
Milliseconds = seconds × 1,000 = microseconds ÷ 1,000 = nanoseconds ÷ 1,000,000
Unit detection: under 12 digits is seconds, under 15 milliseconds, under 18 microseconds, beyond that nanoseconds.
A signed 32-bit seconds field stops at 2,147,483,647 — 19 January 2038.

Pro Tips & Key Considerations

Digit-count detection can be wrong — pick the unit by hand for small values near 1970 or for fractional numbers.Store in UTC and display in local time. Storing local time means a daylight-saving boundary either repeats an hour or loses one.Unix time does not count leap seconds; the same value is reused across an inserted one, so it is the wrong basis for strict second-level intervals.

Frequently Asked Questions (FAQ)

Sources & References

IETF RFC 3339 — Date and Time on the Internet: Timestamps The Open Group POSIX — Seconds Since the Epoch