How the Unix timestamp converter works
Enter a Unix timestamp and the tool shows the matching date and time in your local zone, in UTC, and in ISO 8601 format, plus how long ago or ahead it is. It also works in reverse: pick a date and time and it gives you the timestamp. Everything is computed in your browser.
What a Unix timestamp is
A Unix timestamp counts the seconds elapsed since the start of January 1, 1970 in UTC, known as the epoch. Because it is a single number with no time zone, it is the standard way computers store and compare moments in time, appearing in logs, databases, APIs, and tokens.
Seconds versus milliseconds
Unix time is usually in seconds, but JavaScript and many APIs use milliseconds, which are a thousand times larger and have about thirteen digits instead of ten. If your number looks far in the future, it may be in milliseconds; divide by a thousand. This tool treats your input as seconds.
Time zones and ISO format
The same timestamp shows different wall clock times in different zones, which is why the tool lists both your local time and UTC. ISO 8601 is a standardized text format that sorts chronologically and is unambiguous across systems, making it the safest way to write a date in data you share.
Frequently asked questions
What is a Unix timestamp? The number of seconds since January 1, 1970 UTC, a time zone free way to store moments.
Why is my date wrong by decades? Your value is likely in milliseconds; divide by 1000 to get seconds.
What is ISO 8601? A standard, sortable text date format like the one shown in the output.
Related tools: JSON Formatter, Date Difference, Base64.