René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`Temporal` behavior is not spec-compliant","articleBody":"### Version\n\n26.0.0\n\n### Platform\n\n```text\nDarwin (redacted host name) 25.4.0 Darwin Kernel Version 25.4.0: Thu Mar 19 19:32:36 PDT 2026; root:xnu-12377.101.15~1/RELEASE_ARM64_T8103 arm64\n```\n\n### Subsystem\n\n_No response_\n\n### What steps will reproduce the bug?\n\nbugs for `iso8601` calendar which are already fixed in upstream:\n\n```javascript\n// 1.\nnew Temporal.Duration(0, 1, 0, 0, 1).round({ smallestUnit: 'months', roundingMode: 'expand', relativeTo: new Temporal.PlainDate(2020, 1, 31) }).toString();\n// 2.\nTemporal.Instant.from('2020-01-01T00:00:00.1234567890Z');\n```\n\nincorrect behavior for non-ISO calendars:\n\n```javascript\n// 3.\nTemporal.PlainDate.from({ year: 2020, month: 1, day: 40, calendar: 'gregory' });\n// 4.\nTemporal.PlainDate.from({ year: -1, month: 1, day: 1, calendar: 'gregory' });\n// 5.\nTemporal.PlainDate.from({ year: 5786, monthCode: 'M05L', day: 1, calendar: 'hebrew' });\n// 6.\nTemporal.PlainDate.from('2026-05-01[u-ca=chinese]').year;\n```\n\n### How often does it reproduce? Is there a required condition?\n\nalways, without any conditions\n\n### What is the expected behavior? Why is that the expected behavior?\n\n1. `\"P2M\"`\n2. `RangeError` is thrown\n3. `RangeError` is not thrown\n4. `RangeError` is not thrown\n5. `RangeError` is not thrown\n6. 2026\n\n### What do you see instead?\n\n1. `\"PT0S\"`\n2. `RangeError` is not thrown\n3. `RangeError` is thrown\n4. `RangeError` is thrown\n5. `RangeError` is thrown\n6. 4663\n\n### Additional information\n\nI tested Temporal test cases in test262, and Node.js failed for many cases, mainly due to wrong behavior for non-ISO calendars. I suspect this is because Node.js uses outdated temporal_rs and ICU4X (but I haven't confirmed my guess yet).","author":{"url":"https://github.com/fabon-f","@type":"Person","name":"fabon-f"},"datePublished":"2026-05-06T07:41:18.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":4},"url":"https://github.com/63145/node/issues/63145"}