ISO 8601期間パーサー

An ISO 8601 duration (e.g. P3Y6M4DT12H30M5S) is a compact, unambiguous way to write a time span, used by many APIs and data formats, but hard to read without parsing it. This tool translates such a string into plain language and lets you build one from separate fields.

How to use it

• Parse: paste an ISO duration string to get years, months, days, hours, minutes, and seconds broken out separately, in a readable form.
• Build: enter the duration components you need and the tool assembles a valid ISO 8601 string.
• The letter T before the time part (hours/minutes/seconds) is required and gets added automatically when needed.

Common uses

• Reading a duration field from an API response (a subscription, a rental period, a timeout) given in this format.
• Building a correctly formatted ISO 8601 string for a request that expects a duration in exactly this format.
• Debugging why a third-party API's parser rejects a hand-built duration — checking it against the standard's exact syntax.

Things to keep in mind

The leading P stands for "period" and is required, just like the T that separates days from hours in the time part.

The base standard doesn't define a sign for durations — negative durations (to mean "ago") are only supported by specific implementations as an unofficial extension.