In this article
What Is a Unix Timestamp?
A Unix timestamp (also called epoch time) is the number of seconds that have elapsed since January 1, 1970, at 00:00:00 UTC. It is the most widely used method for representing time in computer systems because it is timezone-independent, stored as a single integer, and easy to do arithmetic on.
Unix timestamps are used in virtually every programming language and database. JavaScript uses milliseconds (divide by 1000 to get seconds), while most other languages use seconds. The year 2038 problem concerns 32-bit systems that will overflow when the timestamp exceeds 2^31.
How Timestamp Conversion Works
The converter translates between Unix timestamps and human-readable dates in both directions.
- Epoch to date — converts a Unix timestamp to a formatted date and time string
- Date to epoch — converts a date/time string to its Unix timestamp equivalent
- Timezone support — displays converted times in UTC and local timezone simultaneously
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Convert a Timestamp →When To Use Timestamp Conversion
Timestamp conversion is useful when working with dates stored as numbers in APIs, databases, or logs.
- API debugging — convert Unix timestamps in API responses to readable dates for inspection
- Log analysis — interpret timestamp fields in log files and database records
- Scheduling — verify that date calculations in code produce the correct Unix timestamp values
Frequently Asked Questions
What is the difference between Unix timestamp in seconds vs milliseconds?
Most Unix systems use seconds. JavaScript's Date.now() returns milliseconds. If a timestamp looks 1000x too large (e.g., 1708600000000 instead of 1708600000), it is in milliseconds. Always check the magnitude and divide by 1000 if working with JavaScript timestamps in a context expecting seconds.
What is the year 2038 problem?
On January 19, 2038, 32-bit signed integers used to store Unix timestamps will overflow, wrapping to a negative value representing 1901. Systems still using 32-bit timestamps will break. Modern systems use 64-bit integers which will not overflow for billions of years.
Are Unix timestamps affected by daylight saving time?
No. Unix timestamps always represent elapsed seconds since the epoch in UTC, regardless of daylight saving time. The DST adjustment only applies when converting to a local time display. This is one of the key advantages of storing times as Unix timestamps.