CLDR 49 Release Note

No.	Date	Rel. Note	Data	Charts	Spec	Delta	GitHub Tag	Delta DTD	CLDR JSON
49	2026-10-XX	v49	~~CLDR49~~	Charts49	LDML49	Δ49	release-49-alpha2	ΔDtd49	49.0.0-ALPHA2

Overview

Unicode CLDR provides key building blocks for software supporting the world’s languages. CLDR data is used by all major software systems (including all mobile phones) for their software internationalization and localization, adapting software to the conventions of different languages.

Changes

The most significant changes in this release are:

Updated for Unicode 18 including annotations for the new emoji, changes to sorting order, etc.
Reflects the most recent updates to external standards and data sources, such as the language subtag registry, UN M49 macro regions, ISO 4217 currencies, etc.
New date & time formatting features including:
- Localized patterns for gluing date & timezoneAppend Items — e.g., Sept 3, EST
- Ordinal days in dates — e.g., Sept 3rd
- Customizing numeric datetime separators in patterns: 3-10-2031 → 3/10/2031
- UTC Timezone Display Patterns
- Dual format for zones with two offsets (summer and winter) — eg, GMT-8/-7
- Deprecated Japanese era data before Meiji
- Structure for preventing digit-digit merges — e.g., ‘2026/1/29 GMT-817时’
- Additional skeleton-patterns added for flexible and interval date formats
- New units (conversions and formatting)
  - 3 new units: Poundal, Dyne, and Milliinch (US mil)
  - 14 new display names in English
- Nested Bracket Replacement — for constructing locale names with parts that have parentheses, eg, ”birmanês (Mianmar [Birmânia])”
- Many additional localized locale option names for use in menus, such as calendar and number-system names
Basic coverage level locale data for 11 new locales: Coptic (moderate), Adyghe, Central Kurdish, Colognian, Kabardian, Kikuyu, Kʼicheʼ, Ladin, Prussian, Qʼeqchiʼ, Sunwar (Sunuwar)

Note: Many enhancements of the CLDR specification (LDML) are due for addition by the CLDR 49 Beta (September 23rd).

For more details, see below.

Locale Coverage Status

Current Levels

Count	Level	Usage	Examples
100	Modern	Suitable for full UI internationalization	Afrikaans, shqip, አማርኛ, ‫العربية‬, հայերեն, অসমীয়া, azərbaycan
12	Moderate	Suitable for “document content” internationalization, eg. in spreadsheet	Akan, Cebuano, Māori, тоҷикӣ
73	Basic	Suitable for locale selection, eg. choice of language on mobile phone	भोजपुरी, बर’, डोगरी, eʋegbe, Gã, हरियाणवी

Note: This includes just the base language and script. There are many more regional variants.

Changes

±	New Level	Locales
📈	Modern	Akan
📈	Moderate	Breton, Coptic
📈	Basic	Adyghe, Central Kurdish, Colognian, Kabardian, Kikuyu, Kʼicheʼ, Ladin, Prussian, Qʼeqchiʼ, Sunwar (Sunuwar)
📉	Moderate*	Romansh, Shan, Tigrinya
📉	Basic*	Bashkir, Faroese, Interlingua, Sardinian, Tajik, Venetian

* Note: Each release, the number of items needed for Modern and Moderate increases. So locales without active contributors may drop down in coverage level. Locales that were below Basic before are bolded.

For a full listing, see Coverage Levels

Specification Changes

Note: Many enhancements of the CLDR specification (LDML) are due for addition by the CLDR 49 Beta (September 23rd).

The following are the most significant changes to the specification (LDML).

Clarified the process of selecting the best dateFormatItem when there is no exact match, and how to use appendItems to add missing fields. This includes a clarification of what are date fields and what are time fields, and a note that appendItems for date and time fields should be appended before combining them.

See the Modifications section of the specification for details.

Data Changes

DTD Changes

For a full listing, see Delta DTDs.

Supplemental Data Changes

For a full listing, see ¤¤BCP47 Delta and ¤¤Supplemental Delta

Locale Changes

Updated en-AU and en-NZ to include exemplar characters for Indigenous languages
Updated AR, CL, PY, UY, and ZM to prefer 24 hour time
Changes to plural and ordinal rules (see Language Plural Rules chart for more information):
- New plural case many for Galician (gl)
- Added plural rules for Tajik (tg), and Vietnamese (vi)
- Fixed bug so Norwegian Nynorsk (nn) inherits plural rules from Norwegian (no)
- Added ordinal rules for Afrikaans (af) and Bulgarian (bg)
- Updated ordinal rules for Spanish (es)
- See plurals tickets for full list
Fixed issue with cross-language inheritance which was giving Haitian Creole an artificially high coverage level.

For a full listing, see Delta Data

Message Format Specification

Collation Data Changes

Number Spellout Data Changes

Addition or improvement of RBNF rules for many locales including Catalan, Italian, Croatian, Greek, Romanian, Ukrainian and more. See RBNF tickets for full list.

Segmentation Data Changes

Transform Data Changes

JSON Data Changes

File Changes

New locale files (28 files, eg. brh.xml)
New test data
- Date/time, decimal, messageFormat (10 files)
- Person name formatting (1 file, br.txt)
- Rule-based number formatting (99 files, eg, af.ssv)
MessageFormat tests/functions (1 file, math.json)
New keyboard files (4 files)
Many new or modified readme files.

Tooling Changes

Keyboard Changes

Migration

The following changes have been made in CLDR 49. Please plan accordingly to avoid disruption.

The pre-Meiji Japanese eras will be removed: There was too much uncertainty in the exact values and feedback that the general practice for exact dates is to use Gregorian for pre-Meiji dates.

Advanced warnings CLDR 50 and beyond

The following changes are planned for CLDR 50. Please plan accordingly to avoid disruption.

Locales which do not have Core data will be removed if still missing core data by alpha. CLDR-16004
Montenegrin cnr will be considered a separate locale and will no longer alias to sr_Latn_ME. CLDR-10769
The default week numbering system will change to follow ISO (where weeks are numbered based on Thursday), instead of being based on the start of the calendar week. The calendar week will be more clearly targeted at matching usage in displayed month calendars. CLDR-18275
The major components in supplementalData.xml and supplementalMetadata.xml files are slated to be organized more logically and moved into separate files. - This will make it easier for implementations to filter out data that they don’t need, and make internal maintenance easier. This will not affect the data, just which file it is located in. Please plan to update XML and JSON parsers accordingly.
For line breaking (and other segmentation types), the UTC is considering publishing new data files that will (a) allow implementations other than ICU/ICU4X to achieve both conformant behavior and high performance, and (b) provide for tailorings (e.g., for CSS profiles) without data duplication. CLDR plans to adopt this tailoring mechanism once the UTC has approved its publication. UTC has a PRI#555 for the current proposal which is open until October 5, 2026. CLDR-18624
UTC is planning on a new specification for UnicodeSet, because it is used across the Unicode encoding specifications (as well as in the higher levels: CLDR, ICU4*). See [UTS #61][]: Unicode Set Notation (currently in draft). It is a much more complete and rigorous specification than what is in the CLDR specification [UTS #35][]. Following UTC approval of [UTS #61][], CLDR plans to deprecate the section in [UTS #35][], and redirect people to the new [UTS #61][]. [UTS #35][] will retain a short description, and make sure that all the links redirect reasonably. CLDR-18624

Known Issues

ISO 3166-2 subdivision codes for Iran changed in 2020, and there are not yet new equivalent stable codes. See CLDR-19060 for more details.
Keyboard: Normalization-safe segments definition does not cover all normalization cases. CLDR-19218

Acknowledgments

Many people have made significant contributions to CLDR and LDML; see the Acknowledgments page for a full listing.

The Unicode Terms of Use apply to CLDR data; in particular, see Exhibit 1.

For web pages with different views of CLDR data, see http://cldr.unicode.org/index/charts.