[Bug]: Date formatting falls back to English for Galician (gl) locale in email invitations

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Calendar invitation emails show dates in English when the user language is set to Galician (gl). All other translations in the email are correct.

Root cause:
Nextcloud uses the punic/punic library for date formatting (3rdparty/punic/punic/src/data/), but Punic does not include data for the gl locale. As a result, date formatting silently falls back to English.

CLDR has full data for Galician:
https://github.com/unicode-org/cldr/blob/main/common/main/gl.xml

MomentJS also has full support for gl:
https://github.com/moment/moment/blob/2.18.1/locale/gl.js

Reported to Punic: punic/punic#424

Steps to reproduce

1. Set user language to Galician (gl)
2. Create a calendar event and invite an external email address
3. Check the received invitation email — date is in English

Expected: martes, 28 de abril de 2026
Actual: Tuesday, April 28, 2026

Expected behavior

Expected: martes, 28 de abril de 2026
Actual: Tuesday, April 28, 2026

Nextcloud Server version

32

Operating system

Other

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "check_data_directory_permissions": false,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "overwritehost": "nube.roicou.gal",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "nube.roicou.gal"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "32.0.8.2",
        "overwrite.cli.url": "https:\/\/nube.roicou.gal\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "updatechecker": false,
        "loglevel": 2,
        "log_type": "file",
        "logfile": "\/var\/www\/html\/data\/nextcloud.log",
        "log_rotate_size": 10485760,
        "log.condition": {
            "apps": [
                "admin_audit"
            ]
        },
        "preview_max_x": 2048,
        "preview_max_y": 2048,
        "jpeg_quality": 60,
        "enabledPreviewProviders": {
            "1": "OC\\Preview\\Image",
            "2": "OC\\Preview\\MarkDown",
            "3": "OC\\Preview\\MP3",
            "4": "OC\\Preview\\TXT",
            "5": "OC\\Preview\\OpenDocument",
            "6": "OC\\Preview\\Movie",
            "7": "OC\\Preview\\Krita",
            "0": "OC\\Preview\\Imaginary",
            "23": "OC\\Preview\\ImaginaryPDF"
        },
        "enable_previews": true,
        "upgrade.disable-web": true,
        "mail_smtpmode": "smtp",
        "trashbin_retention_obligation": "auto, 30",
        "versions_retention_obligation": "auto, 30",
        "activity_expire_days": 30,
        "simpleSignUpLink.shown": false,
        "share_folder": "\/Shared",
        "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
        "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
        "updatedirectory": "\/nc-updater",
        "maintenance_window_start": 100,
        "allow_local_remote_servers": true,
        "davstorage.request_timeout": 3600,
        "documentation_url.server_logs": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/5425",
        "htaccess.RewriteBase": "\/",
        "dbpersistent": false,
        "auth.bruteforce.protection.enabled": true,
        "ratelimit.protection.enabled": true,
        "files_external_allow_create_new_local": false,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "onlyoffice": {
            "editors_check_interval": 0,
            "jwt_secret": "***REMOVED SENSITIVE VALUE***",
            "jwt_header": "AuthorizationJwt"
        },
        "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
        "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
        "config_preset": 2,
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpauth": true,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "default_language": "gl",
        "default_locale": "gl",
        "forbidden_filename_characters": [
            "\\",
            "\/"
        ],
        "forbidden_filename_extensions": [
            ".filepart",
            ".part"
        ],
        "DOMAIN": "nube.roicou.gal",
        "AIO_VERSION": "v12.9.2"
    }
}

List of activated Apps

Enabled:
  - activity: 5.0.0
  - admin_audit: 1.22.0
  - bruteforcesettings: 5.0.0
  - calendar: 6.2.2
  - circles: 32.0.0
  - cloud_federation_api: 1.16.0
  - comments: 1.22.0
  - contacts: 8.3.7
  - contactsinteraction: 1.13.1
  - dashboard: 7.12.0
  - dav: 1.34.2
  - deck: 1.16.3
  - federatedfilesharing: 1.22.0
  - federation: 1.22.0
  - files: 2.4.0
  - files_downloadlimit: 5.0.0
  - files_fulltextsearch: 32.0.2
  - files_pdfviewer: 5.0.0
  - files_reminders: 1.5.0
  - files_sharing: 1.24.1
  - files_trashbin: 1.22.0
  - files_versions: 1.25.0
  - firstrunwizard: 5.0.0
  - fulltextsearch: 32.0.0
  - fulltextsearch_elasticsearch: 32.0.2
  - guests: 4.6.0
  - logreader: 5.0.0
  - lookup_server_connector: 1.20.0
  - nextcloud-aio: 0.8.0
  - nextcloud_announcements: 4.0.0
  - notes: 4.13.1
  - notifications: 5.0.0
  - notify_push: 1.3.1
  - oauth2: 1.20.0
  - password_policy: 4.0.0
  - photos: 5.0.0
  - privacy: 4.0.0
  - profile: 1.1.0
  - provisioning_api: 1.22.0
  - recommendations: 5.0.0
  - related_resources: 3.0.0
  - richdocuments: 9.0.5
  - serverinfo: 4.0.0
  - settings: 1.15.1
  - sharebymail: 1.22.0
  - support: 4.0.0
  - survey_client: 4.0.0
  - systemtags: 1.22.0
  - tasks: 0.17.1
  - text: 6.0.1
  - theming: 2.7.0
  - twofactor_backupcodes: 1.21.0
  - twofactor_totp: 14.0.0
  - updatenotification: 1.22.0
  - user_status: 1.12.0
  - viewer: 5.0.0
  - weather_status: 1.12.0
  - webhook_listeners: 1.3.0
  - workflowengine: 2.14.0
Disabled:
  - app_api: 32.0.0 (installed 32.0.0)
  - encryption: 2.20.0
  - files_external: 1.24.1
  - suspicious_login: 10.0.0
  - twofactor_nextcloud_notification: 6.0.0
  - user_ldap: 1.23.0

Nextcloud Signing status

Nextcloud Logs

Additional info

Installation method: Nextcloud AIO (Docker)
Host OS: Fedora Server

Start by inspecting the locale data under 3rdparty/punic/punic/src/data/ and the email invitation date-formatting entry point. Reproduce the Galician calendar invitation and compare its date with the expected localized wording; done means invitation dates use Galician rather than English, with coverage for the gl locale if the relevant tests are found.