Unix Time Calculator
Convert Unix timestamps to human-readable dates and do quick timestamp math. Enter any epoch value, optionally add or subtract time, and see the result in UTC, ISO 8601, and more. Handy for debugging logs, scheduling jobs, or comparing event times.
Unix time (also called epoch time or POSIX time) counts the seconds since midnight UTC on January 1, 1970. It is the standard way computers track time internally.
Why timestamp arithmetic matters: Developers frequently need to answer questions like "what time was 3600 seconds before this log entry?" or "what is the timestamp 7 days from now?" This calculator lets you add or subtract any duration from a given timestamp.
Common Durations in Seconds:
| Duration | Seconds |
|---|---|
| 1 minute | 60 |
| 1 hour | 3,600 |
| 1 day | 86,400 |
| 1 week | 604,800 |
| 30 days | 2,592,000 |
| 365 days | 31,536,000 |
Timestamps vs. Milliseconds: Many programming languages (JavaScript, Java) use milliseconds since epoch instead of seconds. Multiply a Unix timestamp by 1,000 to get the millisecond version, or divide a millisecond timestamp by 1,000 to get standard Unix time.
Tip: If a timestamp has 13 digits, it is probably in milliseconds. A 10-digit timestamp is in seconds.