Unix Timestamp Converter

Written byOleh Soloninupdated 25 September 2026

Mode

Timestamp (sec or ms)

Result

ISO 8601 (UTC)2026-07-08T00:00:00.000Z
Date (UTC)Wed, 08 Jul 2026 00:00:00 GMT
Detected asseconds
Days from now-90.96

Seconds since 1970, translated

Convert Unix timestamps to readable UTC dates or turn a date into epoch seconds. Detects automatically whether you pasted seconds or milliseconds.

Logs, APIs and databases store time as a single number: seconds elapsed since 1 January 1970 UTC. It is compact and timezone-free, and completely unreadable at a glance.

The persistent trap is seconds versus milliseconds. JavaScript works in milliseconds while most backends use seconds, so a value can land you in 1970 or in the year 56000. This tool detects which one you pasted.

How to use

Pick the direction: timestamp to date, or date to timestamp.
Enter the timestamp — the converter works out the unit from the digit count and tells you what it assumed.
For the reverse, set the date and time; both are read as UTC, not as your local time.

Numbers worth recognising

A timestamp is a single number: seconds since 00:00 UTC on 1 January 1970. It carries no time zone and no daylight saving — both appear only when it is displayed. That makes it the unambiguous choice for logs and APIs and an awkward one for documents meant for people.

The fourth row is the famous one: 2,147,483,647 is the largest number a signed 32-bit field can hold. One second later such a field overflows, goes negative and reads 13 December 1901.

Every date comes from the converter on this page. Zero is a real moment, the start of the epoch; but when a 1970 date turns up in a log, first check whether it is an empty field read as a zero.
Timestamp	Date in UTC	Why it is notable
0	1970-01-01 00:00:00	the epoch itself
1000000000	2001-09-09 01:46:40	the first billion seconds
1783468800	2026-07-08 00:00:00	the example in the field
2147483647	2038-01-19 03:14:07	the end of a 32-bit field

Seconds or milliseconds

JavaScript and Java count in milliseconds; Unix, PHP and most databases count in seconds. A factor of a thousand separates them, and a mix-up shows at once: instead of 2026 you get 1970, or a year tens of thousands of years away.

The converter decides by digit count: a present-day timestamp is ten digits in seconds and thirteen in milliseconds. The "detected as" line says which unit it chose, so the decision can be checked.

Both rows come from the converter on this page — one date written in two units. The "days from today" line counts from the current date, so it changes every day.
Value	Digits	Detected as	Date in UTC
1786752000	10	seconds	2026-08-15 00:00
1786752000000	13	milliseconds	2026-08-15 00:00

What this calculator shows

The ISO 8601 UTC timestamp and a human-readable date
Seconds or milliseconds guessed from the size of the number — for historical values, pick the unit yourself
How many days the timestamp sits from today

What to keep in mind

All output is UTC, deliberately — epoch time carries no timezone.
Values above roughly 10¹² are treated as milliseconds.

FAQs

How do I tell seconds from milliseconds?

By length. Current timestamps in seconds have 10 digits; in milliseconds they have 13. This tool decides for you and tells you which it assumed.

Why does the time not match my clock?

Because the display is UTC. London is on UTC in winter and an hour ahead in summer; New York is four or five hours behind. The timestamp knows nothing of this — the difference appears only when it is shown.

Why 1970?

Unix engineers needed an arbitrary origin and picked the start of the decade they were working in. It stuck, and now most of computing counts from it.

What is the year 2038 problem?

The last second a signed 32-bit integer can hold is 03:14:07 UTC on 19 January 2038; the next one overflows it and wraps round to 1901. Modern systems use 64-bit time, which runs for longer than the universe has existed.

Does epoch time include leap seconds?

No, and that is intentional. Unix time pretends every day has exactly 86,400 seconds, which keeps arithmetic simple at the cost of being fractionally out of step with astronomical time.

Can a timestamp be negative?

Yes — the moment is then before 1970: −86,400 is 31 December 1969. Most programming languages handle it; some database columns do not, because they only accept values from zero.

Worked example

The start of epoch time

Input: 0

Output: 1970-01-01T00:00:00.000Z

Note: Zero is a valid timestamp — the start of the Unix epoch. But an unexpected 1970 in a log may be a missing value read as zero, or a seconds-and-milliseconds mix-up; check the source.

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Unix Timestamp Converter

Result

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