ISO-8601 duration

Client

Convert P1DT2H style strings into labeled parts and plain English—or fill years through seconds and copy a normalized duration. Negative values use a leading minus before P.

What this handles

ISO-8601 durations start with P. Calendar units Y, M, W, D appear in the date section. If you include clock units, add T then H, M, S. Decimal fractions use . or , on the last segment you type.

Related tools

For instants and epochs, use the Unix timestamp converter. For repeating schedules, use Cron helper and World clock when comparing zones.

?

Starts with P; date units (Y M W D) before an optional T, then H M S. Examples: PT1H, P3W, P1Y2MT3M (1 year 2 months + 3 minutes).

Result

Human-readable: 1 day, 2 hours, 30 minutes

Normalized: P1DT2H30M

Common use cases

  • Read JWT exp/nbf style offsets when docs say “duration” alongside Unix timestamps.
  • Normalize vendor strings (P1DT12H vs PT36H) into one canonical spelling for logs.
  • Draft subscription or trial lengths in API specs without guessing separator rules.
  • Cross-check cron or wall-clock tools: durations describe spans; crons describe schedules.

Common mistakes to avoid

  • Confusing M before T with M after T

    Before T, M is months. After T, M is minutes. Always locate the T boundary in the string.

  • Expecting a single fixed length in seconds for Y or M

    Years and months are calendar-dependent; this page keeps them as labeled components, not totals.

  • Mixing weeks with other date units in strict profiles

    Some specs prefer P7D over P1W when combining with other date parts. Normalize carefully for your standard.

FAQ

Is input sent to a server?

No. Parsing and formatting run only in your browser tab.

Do you validate against a JSON Schema duration pattern?

This tool follows common ISO-8601 duration text rules (P…, optional T for time). Edge cases in your schema may differ—compare with your validator.

How does this relate to the timestamp tool?

Timestamps are instants; durations are lengths. Add a duration to an instant in your application code or calendar library.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • iso 8601 duration parser online
  • parse pt1h duration in browser
  • iso8601 duration human readable
  • build iso duration p1dt string

More tools

Related utilities you can open in another tab—mostly client-side.