Duration Calculator
Paste ISO dates or Unix timestamps. Companion to the epoch converter.
Related Tools
How to Calculate Time Between Two Dates
This duration calculator subtracts two dates or Unix timestamps and reports the difference in days, hours, minutes, and seconds, plus a human-readable summary. It uses the browser’s Date and Intl APIs — nothing is sent to a server.
The epoch converter tells you what a single timestamp is. This tool tells you how long it is between two of them. Useful for SLAs, cache ages, billing periods, and rate-limit windows.
Tips
- Paste Unix seconds or milliseconds — 10-digit values are treated as seconds, 13-digit as milliseconds.
- Daylight saving can make “24 hours” not equal “one calendar day”. The breakdown shows both elapsed time and calendar components.
- Use ISO 8601 (
2026-09-04T18:00:00Z) when you need an unambiguous instant.