How it works
The Unix timestamp is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC (the "epoch"). It is the most common way to store an instant in databases, logs, and APIs, because it is a simple number independent of the time zone.
This tool automatically detects the input format: it accepts a timestamp in seconds or milliseconds, an ISO 8601 date (2001-09-09T01:46:40Z), or any recognizable date, and converts it to all the other formats at once.
Besides the list of formats, it shows a complete breakdown: year, month, day, hour, day of the week, day of the year, ISO week, quarter, whether it is a leap year, and your browser's time zone. All computation happens locally on your device.
Examples
10000000002001-09-09T01:46:40.000ZA timestamp in seconds. The same instant in milliseconds would be 1000000000000.01970-01-01T00:00:00.000ZThe value 0 corresponds to the start of the Unix epoch.2024-02-29February 29, 2024 — leap yearIt also accepts dates in ISO format and computes derived data such as the day of the year or the ISO week.Use cases
- Interpret a timestamp that appears in a log or an API response and find out which real date it corresponds to.
- Get the current timestamp to use it in tests, seeds, or default values.
- Convert between a readable date and its ISO 8601 or Unix representation when debugging time zone differences.
Frequently asked questions
How does it distinguish seconds from milliseconds?
By the magnitude of the number. A timestamp in seconds from the current epoch has 10 digits; in milliseconds it has 13. The tool interprets large values as milliseconds.
What is UTC time and how does it differ from local time?
UTC is the world reference time, with no time offset. Local time applies your browser's time zone and daylight saving. The same timestamp represents the same instant in both; only how it is displayed changes.
What is the ISO 8601 week?
It is a week numbering in which the week starts on Monday and week 1 of the year is the one that contains its first Thursday. That is why the first days of January can belong to the last week of the previous year.
Does the year 2038 limit affect me?
The "year 2038 problem" affects systems that store the timestamp in a signed 32-bit integer, which overflows on January 19, 2038. This tool uses JavaScript numbers, so it does not have that limit.