ISO 8601 Converter
Convert dates and durations to and from ISO 8601 format.
Date → ISO 8601 string
Enter a valid date.
ISO 8601 string → Date
Invalid ISO 8601 string.
Parse ISO 8601 duration
Build ISO 8601 duration
About the ISO 8601 Converter
Convert between local dates and ISO 8601 date-time strings, and parse or build ISO 8601 durations in the PnYnMnDTnHnMnS format.
Examples
ISO duration
P1Y2M10DT2H30M0SOutput
1 year, 2 months, 10 days, 2 hours, 30 minutesRelated tools
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Frequently asked questions
Read more
- Timezones, UTC and ISO 8601: dates without bugs
Why 'store dates in UTC' is only half the rule, how ISO 8601 avoids ambiguity, and the daylight saving edge cases that break naive code.
Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser