What is the basic format of an ISO 8601 duration?

It follows the pattern PnYnMnDTnHnMnS, where P is the duration designator, Y/M/D represent date units, T is the time designator, and H/M/S represent time units.

Can I mix weeks with other units in ISO 8601?

No, standard ISO 8601 rules state that weeks (W) should not be combined with other date or time units like years, months, or days.

Where can decimal fractions be used in a duration string?

Decimals are only permitted on the smallest, final unit present in the duration string, such as PT1.5H or PT1H30.5M.

What does the 'T' designator signify in the duration string?

The 'T' designator separates date units (Years, Months, Days) from time units (Hours, Minutes, Seconds) to prevent ambiguity between Months (M) and Minutes (M).

Does this tool support negative durations?

The tool validates standard ISO 8601 duration components and outputs canonical positive intervals based on the input provided.

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ISO 8601 Duration Builder

Convert between natural-language durations and ISO 8601 durations (PnYnMnDTnHnMnS) in both directions with validation of edge cases

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What this tool helps you do

Bidirectional converter for ISO 8601 durations. Natural language (e.g. "3 years 2 months 14 days", "2h30m", "3天2小时") parses to canonical P3Y2M14D; ISO strings parse back to readable form with per-component breakdown. Validates the tricky ISO 8601 rules (T-section units, weeks not combined with Y/M/D, decimal only on smallest unit, at least one component).

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ISO 8601 Duration Builder

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1. Convert Natural Language to ISO 8601

2. Parse ISO 8601 Duration to Human-Readable Text

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