Duration Calculator
Enter a start and end instant (ISO strings, timestamps, or strings your browser can parse). The tool shows the difference in days, hours, minutes, and seconds.
Duration between two dates
How this is calculated
Both values are parsed with the JavaScript Date constructor, then the difference is taken in milliseconds and broken into larger units. Leap seconds and time zones follow normal browser rules for the strings you provide.
Quick tips
- Validate one known sample first, then batch-process the rest.
- Keep timezone and locale assumptions explicit in your test input.
- Copy both source and output when sharing debugging context.
Use this tool for
- Measuring how long a deployment window lasted.
- Checking SLA windows between two logged timestamps.
- Quick sanity checks when debugging date handling.
Common questions
Which inputs matter most for Duration Calculator?
Use the fields this page exposes for your task—usually the main text/box or mode selector—and any option that changes parsing rules.
