Unix Timestamp Converter
Unix time counts seconds since 1970-01-01 00:00:00 UTC. Millisecond timestamps are seconds x 1000.
Choose timestamp or date mode
Enter a Unix timestamp to convert it into a readable date and time. Or enter a date and time to convert it back into a Unix timestamp.
Use this for logs, APIs, databases, analytics exports and debugging. Check whether your value is in seconds or milliseconds before converting.
If the source is JavaScript, the value is often milliseconds. If the source is a Unix command or many APIs, it may be seconds.
When debugging, keep the original value unchanged. Try conversion settings on a copy so you do not lose the source timestamp.
UTC first, local time second
A Unix timestamp counts time from January 1, 1970 at 00:00:00 UTC. A timestamp does not store a local time zone label by itself.
The same timestamp can be displayed as different local times depending on the time zone you choose. The instant is the same. The local label changes.
That makes timestamps good for storage and comparison. Formatting them for people is a separate display step.
Seconds versus milliseconds
A seconds timestamp counts whole seconds since the Unix epoch. A milliseconds timestamp counts thousandths of a second since the same point.
To convert milliseconds to seconds, divide by 1000. To convert seconds to milliseconds, multiply by 1000. Date display then applies UTC or a chosen local time zone.
The numeric conversion should happen before choosing a display zone. Unit mistakes are much larger than time zone offsets.
Converting a 10-digit timestamp
The timestamp 0 represents 1970-01-01 00:00:00 UTC. A value of 3600 represents one hour after that, which is 1970-01-01 01:00:00 UTC.
If your value has 13 digits, it is likely milliseconds. If it has 10 digits for modern dates, it is likely seconds.
For example, 1710000000 is a seconds style value, while 1710000000000 is the matching milliseconds style shape.
The extra three zeros represent thousandths of a second. They are not a time zone adjustment.
The 13-digit timestamp trap
The biggest mistake is using milliseconds in a seconds field. A 13 digit value entered as seconds can produce a date far in the future.
Another mistake is forgetting that Unix timestamps are usually UTC based. If a local display looks off by several hours, check the time zone setting before changing the timestamp.
Unix Timestamp Converter FAQ
What is a Unix timestamp?
A Unix timestamp is a number that counts time since 1970-01-01 00:00:00 UTC. It is widely used by computers because numbers are easy to store, sort and compare.
The timestamp itself is not a formatted calendar date. A converter turns it into a readable date for humans.
Is my timestamp in seconds or milliseconds?
Modern Unix timestamps in seconds are often 10 digits. Timestamps in milliseconds are often 13 digits. That digit count is a quick clue.
If the converted date looks wildly wrong, switch the seconds or milliseconds setting and check again.
A date far in the future often means milliseconds were treated as seconds. A date near 1970 often means seconds were treated as milliseconds.
Why does the timestamp show a different local time?
The timestamp represents one UTC based instant. When you display it in a local time zone, the clock time changes to match that location.
This is expected. The timestamp did not change. Only the display time zone changed.
Does Unix time include leap seconds?
Most everyday Unix timestamp systems do not represent leap seconds the way civil time standards discuss them. They count a continuous sequence of seconds used by computer systems.
For normal web, log and API work, use the timestamp convention expected by the system you are reading or writing.
How can I check a timestamp conversion?
Check the unit first, seconds or milliseconds. Then check the display time zone, UTC or local. Those two settings explain most surprising results.
If both are correct, compare the converted date with another trusted tool or the source system that produced the timestamp.