Timestamp converter
Convert Unix timestamps (s/ms) and dates both ways.
A log line reads 1782345600 and you need to know whether that incident happened before or after the deploy. Or an API expects a timestamp and you have a date on a calendar. This page converts in both directions and keeps the current Unix time on screen, so the number you need is usually one click away.
How it works
Both directions
Paste a number into the Unix timestamp field to get the corresponding date and time. Use the date and time picker to go the other way and get the timestamp for a moment you choose. The current Unix time is displayed at the top and updates as you watch; the copy button next to it puts the value in seconds on your clipboard, which is what most APIs and database columns expect.
Seconds or milliseconds, detected for you
Unix time counts from 1 January 1970 UTC. Some systems count seconds, others milliseconds, and the same instant therefore appears as a 10-digit or a 13-digit number. The field detects which you pasted by its length rather than making you choose, so a value copied from a JavaScript Date.now() and one copied from a PHP time() both resolve correctly. If a date comes out around 1970, the number was almost certainly milliseconds read as seconds — or the other way round for a date far in the future.
Time zones
The converted date is shown in your device's local time zone, while the timestamp itself is an absolute point in time with no zone attached. Two people converting the same number in different countries will see different clock times and both are right. When a timestamp needs to be unambiguous in a document or a ticket, write the UTC offset alongside it.
Terms explained
- Unix timestamp
- The number of seconds elapsed since 1 January 1970 00:00:00 UTC, known as the epoch.
- Epoch
- The zero point of the count — midnight UTC at the start of 1 January 1970.
- Milliseconds
- A thousandth of a second. JavaScript and Java report time in milliseconds, giving 13-digit values instead of 10-digit ones.
- UTC
- Coordinated Universal Time, the reference zone timestamps are measured from. Local time is UTC plus or minus an offset.
- ISO 8601
- The standard textual date format, such as `2026-08-31T12:00:00+09:00`, used when a date has to be readable and unambiguous.
- Year 2038 problem
- The point where a signed 32-bit seconds counter overflows. Modern 64-bit systems are unaffected, but old code and legacy columns may not be.
Frequently asked questions
How do I tell seconds from milliseconds?
Count the digits. Timestamps for dates around now are 10 digits in seconds and 13 in milliseconds. This tool checks the length for you, so both paste in without a setting to change.
Which time zone is the converted date in?
Your device's local zone. The timestamp itself carries no zone — it is an absolute instant — so the same number displays as different clock times in different countries.
The date came out as 1970. What went wrong?
A millisecond value was read as seconds, or the field received something that is not a number. A 13-digit value interpreted as seconds lands tens of thousands of years ahead; a small number lands right after the epoch.
Does a Unix timestamp account for leap seconds?
No. Unix time deliberately ignores leap seconds and treats every day as exactly 86,400 seconds, which keeps arithmetic simple at the cost of a tiny divergence from astronomical time.
Can I convert a date before 1970?
Dates earlier than the epoch are represented as negative timestamps. Support varies between languages and databases, so if you work with historical dates, check how your storage layer handles negative values.
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