How to use this developer tool
- Paste or type a value in the input area.
- Choose the conversion option when one is available.
- Select Parse Duration or press Ctrl/Cmd + Enter.
- Review the interpretation and copy or download the result.
Duration ISO8601 Parser
Break an ISO 8601 duration into years, months, weeks, days, hours, minutes, and fractional seconds. The report preserves calendar-dependent units instead of pretending that every month has the same length. When the input contains only weeks, days, and clock units, it also calculates an exact total in seconds and milliseconds.
Developer Input
ISO 8601 durationAd space
What this developer tool does
ISO 8601 durations use P for the date section and T before time fields. M means months before T and minutes after T.
Match the ordered duration components, reject empty or mixed week forms, and total only units with fixed lengths.
Years and months need a starting calendar date before they can be converted to an exact number of seconds.
Example
Try the sample input, then run the converter. The output panel reports the normalized value and the fields used to derive it.
P1Y2M3DT4H5M6.75S
Use cases
- Inspect values copied from logs, headers, or API payloads.
- Normalize configuration before committing it.
- Compare timestamp representations during debugging.
- Create a reproducible test fixture for date-handling code.
Tips for reliable output
- Include an explicit UTC marker or numeric offset for portable instants.
- Keep the original input beside a converted value during debugging.
- Test boundary dates near midnight and New Year.
- Do not assume a fixed offset carries daylight-saving rules.
- Confirm the consumer uses the same token or date standard.
Processing details
Match the ordered duration components, reject empty or mixed week forms, and total only units with fixed lengths.
Years and months need a starting calendar date before they can be converted to an exact number of seconds.
Frequently asked questions
What input does the Duration ISO8601 Parser accept?
Use the format shown in the sample. The parser rejects empty input and reports malformed values instead of guessing silently.
Does the Duration ISO8601 Parser use my local timezone?
UTC and offset-aware values represent a fixed instant. Any output labeled local uses the timezone configured in your browser.
Can I use the output in production code?
The output is copy-ready, but verify it against the date library and runtime used by your application, especially for legacy formats.
Why can date results differ between browsers?
Browsers may ship different timezone database versions and may parse non-standard legacy date strings differently. Prefer explicit standard formats.
Is my date or duration uploaded to a server?
No. The conversion runs in this page with browser APIs and does not require a network request.
Related developer tools
Time format reference
| Value | Meaning |
|---|---|
| UTC | Coordinated Universal Time |
| Unix epoch | 1970-01-01T00:00:00Z |
| ISO 8601 | International date and time notation |