What Unix time is
Unix time — also called epoch time — counts the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, ignoring leap seconds. It is the standard way computers store moments in time because it is just a single number, free of time zones and calendar quirks. Databases, logs, APIs, and programming languages use it constantly, which is why developers frequently need to translate it to and from readable dates.
Seconds versus milliseconds
Some systems store epoch time in seconds and others in milliseconds (seconds times one thousand). The difference is three digits: a 10-digit value is almost certainly seconds, while a 13-digit value is milliseconds. This converter auto-detects the unit — values with 12 or more digits are treated as milliseconds — so you can paste either without converting first. JavaScript and Java use milliseconds; Unix shells and many databases use seconds.
Local time versus UTC
A timestamp is a fixed instant, but how you read it depends on your time zone. The converter shows both your local time and UTC so you can see the moment in your own terms and in the universal reference that servers use. This dual view helps when debugging logs written by a server in another zone, or when coordinating an event time across regions.
A worked example
The timestamp 1783123200 (10 digits, so seconds) converts to Thursday, 2 July 2026 at 16:00 UTC. Paste 1783123200000 and the tool recognizes the 13-digit value as milliseconds and returns the same instant. Going the other way, pick a date and time and the converter returns its epoch value in seconds, ready to drop into a database query or API call.
Where you'll use it
Developers use epoch conversion to read log timestamps, set token expiry times, debug API responses, and store dates compactly. Analysts use it to make exported data human-readable. Because the live counter shows the current epoch second by second, it is also a quick way to grab "now" as a timestamp for testing. Everything runs locally, so even sensitive log values never leave your machine.