ISO 8601 Formatter
Convert dates to all ISO 8601 format variants
Ensure your dates comply with the ISO 8601 international standard. Parse dates from various formats into strict ISO 8601, or convert ISO dates to other human-readable formats.
Key Features
- ✓Parse any date string into ISO 8601
- ✓Validate existing ISO 8601 dates
- ✓Output variants: basic, extended, date-only, with offset
- ✓Duration format support (P1Y2M3DT4H5M6S)
- ✓Week numbering format (2026-W11-4)
- ✓Copy formatted output instantly
How to ISO 8601 Formatter
- 1
Enter a date in any format
Type or paste a date string — the parser supports dozens of common formats.
- 2
Select the ISO 8601 variant
Choose extended (2026-03-13), basic (20260313), with time, or duration format.
- 3
View the formatted result
See the properly formatted ISO 8601 string with optional timezone offset.
- 4
Copy the output
Click copy to use the formatted date in your code or document.
Common Use Cases
- •Standardizing dates in API request/response payloads
- •Formatting dates for JSON and XML data interchange
- •Ensuring compliance with international date standards
- •Converting legacy date formats to ISO 8601
Frequently Asked Questions
What is ISO 8601?▼
ISO 8601 is an international standard for representing dates and times (e.g., 2026-03-13T14:30:00Z). It eliminates ambiguity between date formats used in different countries.
What is the difference between basic and extended format?▼
Basic format omits separators (20260313T143000Z) while extended format includes hyphens and colons (2026-03-13T14:30:00Z). Extended is more common.
Does it support duration formatting?▼
Yes. ISO 8601 durations like P1Y2M3DT4H5M6S (1 year, 2 months, 3 days, 4 hours, 5 minutes, 6 seconds) are fully supported.