DateInterval Ambiguity Warning

[roxblnfk]

What was changed

Added warning when Carbon and native DateInterval parse ISO 8601 duration strings differently.

• Added isIso8601DurationFormat() to validate ISO 8601 format
• Modified parse() to compare Carbon vs DateInterval results and emit E_USER_WARNING on mismatch
• Added tests for format detection and warning behavior

Why?

Carbon interprets P2M as "2 minutes" while ISO 8601 standard defines it as "2 months", causing incorrect timer durations. Warning suggests using new \DateInterval() for standard ISO 8601 parsing or adding T separator to clarify intent (e.g., PT2M for minutes).

Checklist

1. Closes [DX] Unexpected behaviour with lax DateInterval string parsing #579
2. How was this tested:
   added tests

---

DateInterval Ambiguity Warning

Added runtime detection for ISO 8601 duration strings where Carbon and native DateInterval produce different parse results.

The SDK internal duration parser uses Carbon's CarbonInterval::fromString() which interprets P2M as "2 minutes", while PHP's native DateInterval follows ISO 8601 standard and parses it as "2 months". This discrepancy causes incorrect timer durations.

When an ambiguous format is detected:

yield Workflow::timer('P2M');
// Warning: Ambiguous duration "P2M": Carbon and DateInterval parse it differently.
// Use new \DateInterval("P2M") for ISO 8601 standard parsing or PT/P prefix to clarify intent.

Resolution:

// Use T separator for time components (hours, minutes, seconds)
yield Workflow::timer('PT2M');  // 2 minutes

// Use natural language for Carbon parsing
yield Workflow::timer('2 minutes');  // 2 minutes
yield Workflow::timer('2 months');   // 2 months

// Use DateInterval instance for ISO 8601 compliance
yield Workflow::timer(new \DateInterval('P2M'));  // 2 months

Warning is triggered only when:

1. Input string matches ISO 8601 duration format
2. Carbon and DateInterval produce different interval values

Natural language formats (e.g., "2 days") are not validated against DateInterval and do not trigger warnings.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
php	Ready	Preview	Comment	Oct 30, 2025 1:26pm