Issues

• DateRangeFormatter prints M12 (release) or panics (debug) when the range pattern uses a different month-name width than the ordinary pattern

  C-datetime
  unicode-org/icu4x#8533 · Filter by author ephoton0210 opened on Oct 1, 2026 · 2.x Priority ⟨P2⟩
  5

• Support CalendarPeriod + Zone in FieldSetBuilder and CompositeFieldSet

  C-datetimeneeds-approvalU-ecma402
  unicode-org/icu4x#8531 · Filter by author sffc-bot opened on Oct 1, 2026
  1

• Implement AsRef/AsMut<T> for Yoke<&(mut) T, _>

  C-zerovecS-small
  unicode-org/icu4x#8518 · Filter by author moulins opened on Sep 24, 2026 · Backlog ⟨P4⟩
  2

• DateTime and ZonedDateTime try_from_str are hard to use

  C-datetimediscuss
  unicode-org/icu4x#8516 · Filter by author sffc opened on Sep 24, 2026

• Need to migrate GitHub Actions off gsutil

  C-processS-small
  unicode-org/icu4x#8505 · Filter by author sffc opened on Sep 17, 2026 · Tech Debt Priority ⟨P2⟩
  1

• zerovec's EncodeAsVarULE::encode_var_ule_write panicking can lead to exception safety violation in VarZeroVecOwned::replace

  unicode-org/icu4x#8493 · Filter by author Evian-Zhang opened on Sep 15, 2026 · 2.4 Release ⟨P1⟩
  

• currency: CurrencyFormatter::try_new_symbol_narrow should fall back to standard symbol before ISO code

  C-numbers
  unicode-org/icu4x#8486 · Filter by author younies opened on Sep 11, 2026

• icu_casemap does not expose edit mappings

  unicode-org/icu4x#8467 · Filter by author taj-p opened on Sep 9, 2026
  2

• [Feature] Support write_to_parts and define a currency Part in CurrencyFormatter

  unicode-org/icu4x#8455 · Filter by author younies opened on Sep 3, 2026

• [Question] Should CurrencyFormatter<CompactDecimalFormatter> support per-currency decimal separator overrides?

  C-numbersdiscuss
  unicode-org/icu4x#8454 · Filter by author younies opened on Sep 3, 2026

• Consider exposing TimeZone::Iso and TimeZone::IsoWithZ from field sets

  C-datetime
  unicode-org/icu4x#8440 · Filter by author sffc opened on Aug 31, 2026

• Support the source attribute from Intl.DateTimeFormat.prototype.formatRangeToParts

  C-datetime
  unicode-org/icu4x#8437 · Filter by author jedel1043 opened on Aug 30, 2026 · 2.4 Release ⟨P1⟩
  3

• Allow obtaining a DateTimeFormatter from DateRangeFormatter

  C-datetime
  unicode-org/icu4x#8436 · Filter by author jedel1043 opened on Aug 30, 2026 · 2.4 Release ⟨P1⟩
  12

• Interop between ICU4X Semantic Skeletons, ICU4C, and ECMA DateTimeFormatter

  C-datetimeS-epic
  unicode-org/icu4x#8434 · Filter by author sffc opened on Aug 29, 2026 · 2.4 Release ⟨P1⟩
  7

• zerovec::ule::cast_box callable in an unsound way from the public API

  unicode-org/icu4x#8408 · Filter by author weiznich opened on Aug 20, 2026
  3

• Is whole-slice validation (validate_bytes) in ULE worth it?

  API-breakingC-zerovec
  unicode-org/icu4x#8399 · Filter by author Manishearth opened on Aug 18, 2026
  7

• Add option for including pseudolocales

  A-dataC-data-infraU-chromium
  unicode-org/icu4x#8398 · Filter by author Manishearth opened on Aug 18, 2026
  5

• CSS text-transform: full-width relies on raw Decomposition_Mapping

  C-collator
  unicode-org/icu4x#8392 · Filter by author SimonSapin opened on Aug 17, 2026
  2

• [icu_datetime] DateRangeFormatter formats fieldset differently when using CompositeFieldSet

  C-datetimeT-bug
  unicode-org/icu4x#8382 · Filter by author Nerixyz opened on Aug 14, 2026 · 2.4 Release ⟨P1⟩
  3

• Feedback Request for Unicode 17 Segmenters

  C-segmentation
  unicode-org/icu4x#8381 · Filter by author sffc opened on Aug 14, 2026
  2

• Investigate performance regression in segmentation benchmarks

  A-performanceC-segmentation
  unicode-org/icu4x#8376 · Filter by author sffc opened on Aug 13, 2026 · 2.4 Release ⟨P1⟩
  

• Consider performance improvements in calendar resolution

  A-performanceC-datetime
  unicode-org/icu4x#8375 · Filter by author sffc opened on Aug 13, 2026 · Tech Debt Priority ⟨P2⟩
  3

• Consider performance improvements in numeric month name loading

  A-performanceC-datetime
  unicode-org/icu4x#8374 · Filter by author sffc opened on Aug 13, 2026 · Tech Debt Priority ⟨P2⟩

• Add Dart FFI tests for unstable features

  C-ffi-infra
  unicode-org/icu4x#8367 · Filter by author sffc opened on Aug 13, 2026
  1

• Investigate improvements to Pattern::interpolate and Pattern::try_interpolate

  C-message
  unicode-org/icu4x#8365 · Filter by author sffc opened on Aug 13, 2026