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Milliseconds to Date Converter

Read a Unix timestamp in milliseconds as a date, with the sub-second part kept in the ISO 8601 line.

Timestamp → Date

Unit

Date → Timestamp

One timestamp or date per line, up to 500.

Convert this timestamp in your own code.

Language

How to Use

Paste the number into the box on the left. The page opens with 1735689600000 as an example.
Unit is already set to Milliseconds, so the value is divided by 1000 rather than guessed at.
Click Convert. You get the date in the selected time zone, in UTC, as ISO 8601, and as a relative time such as 2 years ago.
Change the time zone at the top right to read the same instant somewhere else.

Frequently Asked Questions

How do I tell milliseconds from seconds?

Count the digits. A value in milliseconds has 13 digits for any date between 2001 and 2286, while the same instant in seconds has 10. If a date lands in 1970 you passed milliseconds to something expecting seconds; if it lands tens of thousands of years away, you did the reverse.

Are the milliseconds kept in the result?

In the ISO 8601 line, yes: it ends in a three-digit fraction before the Z. The line for your selected zone and the UTC line both stop at whole seconds, because that is as fine as those formats go.

Can I just divide by 1000?

It works, but anything after the decimal point is gone. Rounding down moves an event recorded at 12:00:00.940 into the same second as one at 12:00:00.001, which is enough to reorder two log lines or make a duration come out a second short.

Why set Unit instead of leaving Auto-detect?

Auto-detect reads the digit count, and a millisecond value from the early 1970s has too few digits to look like one. Fixing the unit makes the reading the same for every value you paste, which matters when the numbers come from one system in a single format.

Convert Epoch Milliseconds to a Date

Updated September 24, 2026 · By Saman

Most of the time values a front-end developer meets are in milliseconds, because that is what the language hands them: Date.now() counts milliseconds, not seconds. Everything downstream, from log pipelines to database columns, then has to agree on the unit. This page opens the Timestamp Converter with the Unit menu already on Milliseconds so a thirteen-digit number reads correctly the moment you paste it.

The answer appears on four lines at once: the instant in whichever zone is selected at the top right, the same instant in <abbr title="Coordinated Universal Time">UTC, the ISO 8601 form that most APIs want back, and the distance from now in plain words. All of it is computed in the page, so values out of a production log stay on your machine.

Thirteen digits, and when counting them is not enough

Auto-detect works from the digit count and is right for anything dated in this century, but the unit is a property of the system that produced the number, not of the number itself. Pin the Unit menu and the guess disappears. The cost of getting it wrong is not subtle, because each step between units moves the date by three orders of magnitude.

Unit chosen for `1735689600000`	Date it produces	Verdict
Seconds	25 October 56971	Off by a factor of 1000 the wrong way
Milliseconds	1 January 2025, 00:00:00 UTC	What the number means
Microseconds	21 January 1970, 02:08:09 UTC	A near-1970 date is the classic symptom
Nanoseconds	1 January 1970, 00:28:55 UTC	Almost the epoch itself

A date in the opening days of 1970 or one in the tens of thousands of years is therefore almost never bad data. It is the same integer read under the wrong unit, and the fix is the menu rather than the number.

Where millisecond timestamps come from

JavaScript: Date.now() and new Date().getTime() both return milliseconds, and new Date(n) expects them, which is why a ten-digit value has to be multiplied by 1000 first.
Java: System.currentTimeMillis() and Instant.toEpochMilli().
MongoDB: the BSON date type is a signed 64-bit count of milliseconds since the epoch.
Kafka, Elasticsearch and most JSON log formats, which inherited the unit from the languages that write into them.

Databases and Unix tooling lean the other way and count in seconds, so the boundary between a JavaScript service and a SQL column is exactly where the factor of 1000 gets lost. Converting a suspect value here and reading the date is the fastest way to see which side dropped it.

Rounding, and converting more than one

Going from milliseconds to seconds is a truncation, so do it in one place and in one direction. Mixing a floor in one service with a round in another produces off-by-one-second differences that only show up when two events land in the same second. The Batch tab under the converter follows the same rule: paste up to 500 lines, and each row gets a Seconds column with the fraction dropped alongside an ISO 8601 column that keeps it, ready to copy as CSV.

Related conversions

For a ten-digit value there is Timestamp to Date, and for the opposite direction Date to Timestamp, which returns both seconds and milliseconds for a date you pick. The current Unix timestamp is the live counter in the toolbar, and Discord timestamps needs the seconds form, which is a common reason to convert down.

Guides

Discord Timestamps: Syntax, Styles and Examples A Discord timestamp is a Unix time in seconds plus a style letter, and every reader sees it in their own time zone and locale.