Free Online Unix Timestamp Converter & Epoch Calculator
This free online Unix timestamp converter and epoch calculator converts timestamps to readable dates in multiple formats. Shows live epoch time. No sign-up.
Current Unix timestamp
—
Unix → Human date
Enter a Unix timestamp to convert it…
Date → Unix
Invalid date
Quick references
Built by
Miguel Ángel Colorado Marin (MACM)
Built by
Miguel Ángel Colorado Marin (MACM)
Full-Stack Developer · Guadalajara, España
I develop web apps, digital tools and full projects — from design to deployment.
How to use the timestamp converter?
- 1
Check the current timestamp
The top section shows the current Unix timestamp, updated every second. Copy it in seconds or milliseconds, or click 'Use in converter' to send it to the Unix → Date panel.
- 2
Convert Unix to a readable date
Enter any Unix timestamp in the left panel. The unit is detected automatically: values above 100,000,000,000 are read as milliseconds and smaller ones as seconds. The result appears in ISO 8601, UTC, local date, relative time and milliseconds.
- 3
Convert a date to Unix
In the right panel, pick a date with the date picker and a time with the time picker. The timestamp in seconds and milliseconds, and the date in ISO 8601, are calculated instantly.
- 4
Use the quick references
At the end of the converter, the references load well-known timestamps (start of 2000, 2024 and 2025, and the 32-bit maximum) to understand the scale of Unix values or make quick comparisons.
What Unix time is
Unix time counts the seconds elapsed since 00:00:00 UTC on 1 January 1970, ignoring leap seconds. Because it is an integer, two instants are compared by subtracting them, and the value does not change depending on where it was generated. That is why it appears in databases, HTTP headers and the exp, iat and nbf claims of JWT tokens.
A value like 1700000000 is 22:13:20 UTC on 14 November 2023, and the same instant in milliseconds is 1700000000000. Negative numbers represent dates before 1970.
Seconds or milliseconds: how detection works
When converting Unix to a date you do not need to state the unit. If the number is greater than 100,000,000,000 it is read as milliseconds; in any other case as seconds. That limit corresponds to the year 5138 if the value were in seconds, so no reasonable seconds timestamp exceeds it. The weak point is the other end: a millisecond value before March 1973 has 11 digits or fewer and is read as seconds. For those dates, divide the value by 1000 before pasting it.
In the Date → Unix panel, the time you choose is read as the browser's local time and converted to the matching UTC instant. The same text can therefore give a different number on a computer set to another time zone, and on daylight saving changeover days a date can shift by one hour. To compare with another zone, convert the value to UTC or use a time zone converter.
Formats shown by the converter
Each Unix-to-date conversion shows five values: ISO 8601 (for example 2023-11-14T22:13:20.000Z), UTC in HTTP header format, local date in your browser's time zone, relative time from now, and the value in milliseconds. ISO 8601 and UTC always use UTC. Relative time is expressed in seconds, minutes, hours or days, rounded.
Quick references and the 2038 limit
The quick references load 946684800 (1 January 2000), 1704067200 (1 January 2024) and 1735689600 (1 January 2025), all at 00:00:00 UTC. The last button loads 2147483647, the largest value of a signed 32-bit integer, which corresponds to 19 January 2038 at 03:14:07 UTC. From that moment, systems that store time in unpatched 32-bit integers overflow.
Frequently asked questions
What is a Unix timestamp?
It is the number of seconds elapsed since 00:00:00 UTC on 1 January 1970. It is an integer that does not depend on the time zone, so two instants are compared by subtracting their values.
What is the difference between seconds and milliseconds?
Classic Unix systems, databases and many APIs use seconds (10 digits in 2024, such as 1700000000). JavaScript and many modern APIs use milliseconds (13 digits, such as 1700000000000). The converter detects the unit from the size of the number: above 100,000,000,000 it is read as milliseconds.
What is the Year 2038 problem?
A signed 32-bit integer reaches at most 2,147,483,647 seconds, which is 19 January 2038 at 03:14:07 UTC. After that the counter overflows and becomes a negative value. 64-bit systems last until the year 292,277,026,596.
Why is the date shown in the wrong time zone?
The timestamp is always UTC. When it is converted to a local date, the browser applies your operating system's time zone. The ISO 8601 and UTC rows always show the time in UTC; the converter does not let you pick another time zone, so use a time zone converter for that.
Is my data sent to any server?
No. Conversion uses JavaScript's native Date object in your browser, and no timestamp or date is sent to an external server.
Related tools
Embed the converter on your site
Embed this timestamp converter in any web page with a simple iframe:
<iframe
src="https://miguelacm.es/embed/timestamp-converter?locale=en"
width="100%"
height="600"
frameborder="0"
title="Timestamp Converter"
></iframe>