Web Tools tools.bryantsmith.com

Dates & Scheduling

ISO 8601 Converter

Paste any ISO 8601 date, time, or timestamp to see exactly what it means, or build a canonical value from parts. Durations are supported too, and nothing leaves your browser.

Runs in your browser Local time

Actions

live

Parse an ISO 8601 value

calendar · week · ordinal

Accepts extended and basic forms, explicit offsets, Z, ISO week dates such as 2024-W05-3, and ordinal dates such as 2024-031.

Normalized ISO 8601

2024-01-31T12:30:45+05:30

Build a timestamp

compose

ISO 8601 output

—

Durations

P…

Try PT1H30M, P2W, P3DT12H, or P1Y6M.

Normalized duration

—

Build a duration from parts
P1Y

How it works

Everything runs in your browser — nothing is uploaded and no external service is called. Values without an explicit offset are treated as floating wall-clock time; the “UTC instant” row interprets them using your device timezone, which is shown above. ISO 8601 also defines week dates (2024-W05-3) and ordinal dates (2024-031), which are converted to calendar dates here. Durations use calendar units: years and months have no fixed length, so their total is marked as an approximation, while weeks, days, hours, minutes, and seconds are exact.

Related tools

  • Unix Timestamp ConverterConvert Unix timestamps to readable dates and back, in seconds or milliseconds, entirely in your browser.
  • Time Zone ConverterConvert a date and time across multiple IANA time zones at once, with daylight saving applied for that date — entirely in your browser.
  • Business Days CalculatorCount business days between two dates with configurable weekends and holiday exclusions — entirely in your browser.
  • Cron Expression BuilderBuild a cron expression visually from scheduling intent and copy it, with plain-language feedback and next run times.
  • Cron Expression ExplainerTranslate cron expressions into plain language with a field-by-field breakdown, warnings, and next run times — all in your browser.
  • Cron Next-Run CalculatorPreview the next execution times for a cron expression in any time zone, entirely in your browser.

More Dates & Scheduling tools