Epoch Timestamp Calculator
A Unix epoch timestamp is a single number that records a moment as the count of seconds since midnight UTC on 1 January 1970. It appears throughout computing, in logs, databases, APIs, and file metadata, because it is compact and timezone-free. This calculator turns a timestamp in seconds into a readable UTC date and time, and breaks the same value down into elapsed days, hours, and minutes since the epoch. Enter any whole number of seconds to see exactly which instant it represents.
Epoch timestamp formula
epoch = 1 January 1970, 00:00:00 UTC
date (UTC) = epoch + timestamp seconds
days since epoch = timestamp / 86,400
hours since epoch = timestamp / 3,600
minutes since epoch = timestamp / 60
One day has 86,400 seconds (24 * 60 * 60). The date conversion uses the browser's UTC date routines, which apply the standard Gregorian calendar with leap years.
Epoch time facts
- The epoch is fixed at 00:00:00 UTC on 1 January 1970, defined by the POSIX standard.
- The timestamp 1,000,000,000 fell on 9 September 2001; 2,000,000,000 falls in May 2033.
- A 32-bit signed timestamp overflows on 19 January 2038 (the year 2038 problem).
- Unix time ignores leap seconds, treating every day as exactly 86,400 seconds.
- Many programming languages and databases store time internally as an epoch timestamp.
Epoch timestamps: frequently asked questions
What is a Unix epoch timestamp?
A Unix timestamp counts the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC) on 1 January 1970, known as the epoch. It is a single integer that uniquely identifies a moment in time, widely used in computing because it is timezone-independent and easy to compare.
How do I convert an epoch timestamp to a date?
Divide the timestamp by 86,400 (the number of seconds in a day) to find the day offset from 1 January 1970, then add the remainder back as hours, minutes, and seconds. This calculator does the full conversion and shows the resulting UTC date and time, plus the breakdown into elapsed days, hours, and minutes.
Is the timestamp in seconds or milliseconds?
Unix timestamps are traditionally in seconds. JavaScript and some other systems use milliseconds (seconds times 1,000). This calculator expects seconds. If your value has 13 digits it is probably milliseconds, so divide it by 1,000 before entering it.
What is the year 2038 problem?
Systems that store the timestamp in a signed 32-bit integer overflow at 2,147,483,647 seconds, which occurs at 03:14:07 UTC on 19 January 2038. After that point the value wraps to a negative number. Modern systems use 64-bit integers, which push the limit billions of years into the future.
Does the timestamp account for leap seconds?
No. Unix time treats every day as exactly 86,400 seconds and ignores leap seconds, so it is technically a count of non-leap seconds. This is the standard behaviour defined by POSIX and is what almost all software assumes.
Official sources
- The Open Group (POSIX): Seconds Since the Epoch.
- National Institute of Standards and Technology (NIST): Leap Seconds.
Reviewed by the CalculatorHub team, edited by James Graham, 16 June 2026. See our methodology.