diff --git a/build-tools-internal/src/main/groovy/elasticsearch.ide.gradle b/build-tools-internal/src/main/groovy/elasticsearch.ide.gradle
index cae1116d37ea..dd8b582adb92 100644
--- a/build-tools-internal/src/main/groovy/elasticsearch.ide.gradle
+++ b/build-tools-internal/src/main/groovy/elasticsearch.ide.gradle
@@ -167,7 +167,7 @@ if (providers.systemProperty('idea.active').getOrNull() == 'true') {
             vmParameters = [
               '-ea',
               '-Djava.security.manager=allow',
-              '-Djava.locale.providers=SPI,COMPAT',
+              '-Djava.locale.providers=SPI,CLDR',
               '-Des.nativelibs.path="' + testLibraryPath + '"',
               // TODO: only open these for mockito when it is modularized
               '--add-opens=java.base/java.security.cert=ALL-UNNAMED',
diff --git a/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ElasticsearchTestBasePlugin.java b/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ElasticsearchTestBasePlugin.java
index 689c8ddecb05..2d6964c041fe 100644
--- a/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ElasticsearchTestBasePlugin.java
+++ b/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/ElasticsearchTestBasePlugin.java
@@ -92,7 +92,7 @@ public abstract class ElasticsearchTestBasePlugin implements Plugin<Project> {
                     mkdirs(test.getWorkingDir().toPath().resolve("temp").toFile());
 
                     // TODO remove once jvm.options are added to test system properties
-                    test.systemProperty("java.locale.providers", "SPI,COMPAT");
+                    test.systemProperty("java.locale.providers", "SPI,CLDR");
                 }
             });
             test.getJvmArgumentProviders().add(nonInputProperties);
diff --git a/distribution/tools/server-cli/src/main/java/org/elasticsearch/server/cli/SystemJvmOptions.java b/distribution/tools/server-cli/src/main/java/org/elasticsearch/server/cli/SystemJvmOptions.java
index 94e2d538c0ad..2d707f150cc8 100644
--- a/distribution/tools/server-cli/src/main/java/org/elasticsearch/server/cli/SystemJvmOptions.java
+++ b/distribution/tools/server-cli/src/main/java/org/elasticsearch/server/cli/SystemJvmOptions.java
@@ -10,6 +10,7 @@ package org.elasticsearch.server.cli;
 
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
+import org.elasticsearch.core.UpdateForV9;
 
 import java.util.List;
 import java.util.Map;
@@ -59,11 +60,7 @@ final class SystemJvmOptions {
                 "-Dlog4j.shutdownHookEnabled=false",
                 "-Dlog4j2.disable.jmx=true",
                 "-Dlog4j2.formatMsgNoLookups=true",
-                /*
-                 * Due to internationalization enhancements in JDK 9 Elasticsearch need to set the provider to COMPAT otherwise time/date
-                 * parsing will break in an incompatible way for some date patterns and locales.
-                 */
-                "-Djava.locale.providers=SPI,COMPAT",
+                "-Djava.locale.providers=" + getLocaleProviders(),
                 maybeEnableNativeAccess(),
                 maybeOverrideDockerCgroup(distroType),
                 maybeSetActiveProcessorCount(nodeSettings),
@@ -75,6 +72,16 @@ final class SystemJvmOptions {
         ).filter(e -> e.isEmpty() == false).collect(Collectors.toList());
     }
 
+    @UpdateForV9    // only use CLDR in v9+
+    private static String getLocaleProviders() {
+        /*
+         * Specify SPI to load IsoCalendarDataProvider (see #48209), specifying the first day of week as Monday.
+         * When on pre-23, use COMPAT instead to maintain existing date formats as much as we can.
+         * When on JDK 23+, use the default CLDR locale database, as COMPAT was removed in JDK 23.
+         */
+        return Runtime.version().feature() >= 23 ? "SPI,CLDR" : "SPI,COMPAT";
+    }
+
     /*
      * The virtual file /proc/self/cgroup should list the current cgroup
      * membership. For each hierarchy, you can follow the cgroup path from
diff --git a/docs/painless/painless-contexts/painless-field-context.asciidoc b/docs/painless/painless-contexts/painless-field-context.asciidoc
index 2f4e27dd11e6..661af8e64d1e 100644
--- a/docs/painless/painless-contexts/painless-field-context.asciidoc
+++ b/docs/painless/painless-contexts/painless-field-context.asciidoc
@@ -64,14 +64,14 @@ actors that appear in each play:
 ----
 GET seats/_search
 {
-  "size": 2, 
+  "size": 2,
   "query": {
     "match_all": {}
   },
   "script_fields": {
     "day-of-week": {
       "script": {
-        "source": "doc['datetime'].value.getDayOfWeekEnum().getDisplayName(TextStyle.FULL, Locale.ROOT)"
+        "source": "doc['datetime'].value.getDayOfWeekEnum().getDisplayName(TextStyle.FULL, Locale.ENGLISH)"
       }
     },
     "number-of-actors": {
@@ -132,4 +132,4 @@ GET seats/_search
   }
 }
 ----
-// TESTRESPONSE[s/"took" : 68/"took" : "$body.took"/]
\ No newline at end of file
+// TESTRESPONSE[s/"took" : 68/"took" : "$body.took"/]
diff --git a/docs/painless/painless-guide/painless-execute-script.asciidoc b/docs/painless/painless-guide/painless-execute-script.asciidoc
index 4417daeb63ef..771a6818d45e 100644
--- a/docs/painless/painless-guide/painless-execute-script.asciidoc
+++ b/docs/painless/painless-guide/painless-execute-script.asciidoc
@@ -749,7 +749,7 @@ POST /_scripts/painless/_execute
 {
   "script": {
     "source": """
-      emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+      emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
     """
   },
   "context": "keyword_field",
diff --git a/docs/reference/aggregations/bucket/composite-aggregation.asciidoc b/docs/reference/aggregations/bucket/composite-aggregation.asciidoc
index 807ec93132d3..ded01237c23c 100644
--- a/docs/reference/aggregations/bucket/composite-aggregation.asciidoc
+++ b/docs/reference/aggregations/bucket/composite-aggregation.asciidoc
@@ -156,7 +156,7 @@ GET /_search
       "type": "keyword",
       "script": """
         emit(doc['timestamp'].value.dayOfWeekEnum
-          .getDisplayName(TextStyle.FULL, Locale.ROOT))
+          .getDisplayName(TextStyle.FULL, Locale.ENGLISH))
       """
     }
   },
diff --git a/docs/reference/aggregations/bucket/datehistogram-aggregation.asciidoc b/docs/reference/aggregations/bucket/datehistogram-aggregation.asciidoc
index 3511ec9e63b0..ef62f263a54a 100644
--- a/docs/reference/aggregations/bucket/datehistogram-aggregation.asciidoc
+++ b/docs/reference/aggregations/bucket/datehistogram-aggregation.asciidoc
@@ -582,7 +582,7 @@ For example, the offset of `+19d` will result in buckets with names like `2022-0
 
 Increasing the offset to `+20d`, each document will appear in a bucket for the previous month,
 with all bucket keys ending with the same day of the month, as normal.
-However, further increasing to `+28d`, 
+However, further increasing to `+28d`,
 what used to be a February bucket has now become `"2022-03-01"`.
 
 [source,console,id=datehistogram-aggregation-offset-example-28d]
@@ -819,7 +819,7 @@ POST /sales/_search?size=0
   "runtime_mappings": {
     "date.day_of_week": {
       "type": "keyword",
-      "script": "emit(doc['date'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+      "script": "emit(doc['date'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
     }
   },
   "aggs": {
diff --git a/docs/reference/indices/index-templates.asciidoc b/docs/reference/indices/index-templates.asciidoc
index 538fb5b97860..66911716ffee 100644
--- a/docs/reference/indices/index-templates.asciidoc
+++ b/docs/reference/indices/index-templates.asciidoc
@@ -102,7 +102,7 @@ PUT _component_template/runtime_component_template
         "day_of_week": {
           "type": "keyword",
           "script": {
-            "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+            "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
           }
         }
       }
diff --git a/docs/reference/mapping/runtime.asciidoc b/docs/reference/mapping/runtime.asciidoc
index dc21fcfb9261..190081fa801b 100644
--- a/docs/reference/mapping/runtime.asciidoc
+++ b/docs/reference/mapping/runtime.asciidoc
@@ -135,7 +135,7 @@ PUT my-index-000001/
       "day_of_week": {
         "type": "keyword",
         "script": {
-          "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+          "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
         }
       }
     },
@@ -291,7 +291,7 @@ GET my-index-000001/_search
     "day_of_week": {
       "type": "keyword",
       "script": {
-        "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+        "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
       }
     }
   },
@@ -667,7 +667,7 @@ PUT my-index-000001/
       "day_of_week": {
         "type": "keyword",
         "script": {
-          "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+          "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
         }
       }
     },
diff --git a/docs/reference/ml/ml-shared.asciidoc b/docs/reference/ml/ml-shared.asciidoc
index 44c2012f502e..97122141d755 100644
--- a/docs/reference/ml/ml-shared.asciidoc
+++ b/docs/reference/ml/ml-shared.asciidoc
@@ -951,7 +951,7 @@ For example:
   "day_of_week": {
     "type": "keyword",
     "script": {
-      "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+      "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
     }
   }
 }
diff --git a/docs/reference/search/search-your-data/search-api.asciidoc b/docs/reference/search/search-your-data/search-api.asciidoc
index 496812a0cedb..98c5a48b7559 100644
--- a/docs/reference/search/search-your-data/search-api.asciidoc
+++ b/docs/reference/search/search-your-data/search-api.asciidoc
@@ -173,7 +173,7 @@ GET /my-index-000001/_search
       "script": {
         "source":
         """emit(doc['@timestamp'].value.dayOfWeekEnum
-        .getDisplayName(TextStyle.FULL, Locale.ROOT))"""
+        .getDisplayName(TextStyle.FULL, Locale.ENGLISH))"""
       }
     }
   },
diff --git a/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/65_runtime_doc_values.yml b/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/65_runtime_doc_values.yml
index 148b8e55e1a4..b5190a579f62 100644
--- a/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/65_runtime_doc_values.yml
+++ b/modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/65_runtime_doc_values.yml
@@ -12,7 +12,7 @@ setup:
                 script:
                   source: |
                     for (date in field('date')) {
-                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                     }
               total_value_double:
                 type: double
@@ -55,7 +55,7 @@ setup:
                   source: |
                     if (doc.containsKey('date')) {
                       for (date in doc['date']) {
-                        emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                        emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                       }
                     }
               doc_total_value_double:
@@ -737,7 +737,7 @@ setup:
               script:
                 source: |
                   for (date in field('date')) {
-                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                   }
           sort: [ { rank: asc } ]
           script_fields:
@@ -758,7 +758,7 @@ setup:
               script:
                 source: |
                   for (date in field('date')) {
-                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                   }
           sort: [ { rank: asc } ]
           script_fields:
@@ -924,7 +924,7 @@ setup:
                 source: |
                   if (doc.containsKey('date')) {
                     for (date in doc['date']) {
-                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                     }
                   }
           sort: [ { rank: asc } ]
@@ -947,7 +947,7 @@ setup:
                 source: |
                   if (doc.containsKey('date')) {
                     for (date in doc['date']) {
-                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                     }
                   }
           sort: [ { rank: asc } ]
@@ -1133,7 +1133,7 @@ setup:
               script:
                 source: |
                   for (date in field('date')) {
-                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                   }
           sort: [ { rank: asc } ]
           script_fields:
@@ -1156,7 +1156,7 @@ setup:
               script:
                 source: |
                   for (date in field('date')) {
-                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                    emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                   }
           sort: [ { rank: asc } ]
           script_fields:
@@ -1337,7 +1337,7 @@ setup:
                 source: |
                   if (doc.containsKey('date')) {
                     for (date in doc['date']) {
-                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                     }
                   }
           sort: [ { rank: asc } ]
@@ -1362,7 +1362,7 @@ setup:
                 source: |
                   if (doc.containsKey('date')) {
                     for (date in doc['date']) {
-                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                      emit(date.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
                     }
                   }
           sort: [ { rank: asc } ]
diff --git a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/10_keyword.yml b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/10_keyword.yml
index 7bd7b6c7779e..11214907eb17 100644
--- a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/10_keyword.yml
+++ b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/10_keyword.yml
@@ -12,7 +12,7 @@ setup:
               day_of_week:
                 type: keyword
                 script: |
-                  emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                  emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
               # Test fetching from _source
               day_of_week_from_source:
                 type: keyword
@@ -75,7 +75,7 @@ setup:
   - match: {sensor.mappings.runtime.day_of_week.type: keyword }
   - match:
       sensor.mappings.runtime.day_of_week.script.source: |
-        emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+        emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
   - match: {sensor.mappings.runtime.day_of_week.script.lang: painless }
 
 # --- TODO get field mappings needs to be adapted
@@ -90,7 +90,7 @@ setup:
 #        type: keyword
 #        script:
 #          source: |
-#            emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+#            emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
 #          lang: painless
 #        meta: {}
 #
diff --git a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/13_keyword_calculated_at_index.yml b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/13_keyword_calculated_at_index.yml
index 1c10a017a5c3..4bedfa3e923a 100644
--- a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/13_keyword_calculated_at_index.yml
+++ b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/13_keyword_calculated_at_index.yml
@@ -21,7 +21,7 @@ setup:
               day_of_week:
                 type: keyword
                 script: |
-                  emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                  emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
               # Test fetching from _source
               day_of_week_from_source:
                 type: keyword
@@ -74,7 +74,7 @@ setup:
   - match: {sensor.mappings.properties.day_of_week.type: keyword }
   - match:
       sensor.mappings.properties.day_of_week.script.source: |
-        emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+        emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
   - match: {sensor.mappings.properties.day_of_week.script.lang: painless }
 
 ---
diff --git a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/40_runtime_mappings.yml b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/40_runtime_mappings.yml
index 0e7d0b78bba4..b6acc7a18345 100644
--- a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/40_runtime_mappings.yml
+++ b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/40_runtime_mappings.yml
@@ -34,7 +34,7 @@ setup:
             day_of_week:
               type: keyword
               script:
-                source: "emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                source: "emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
 
   - match: {indices:                             ["test-1"]}
   - length: {fields.timestamp:                            1}
@@ -78,7 +78,7 @@ setup:
             day_of_week:
               type: keyword
               script:
-                source: "emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                source: "emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
 
   - match: {indices:                    ["test-1", "test-2"]}
   - length: {fields.day_of_week:                          1}
diff --git a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/80_multiple_indices.yml b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/80_multiple_indices.yml
index 0c571975098b..dc52350a25a7 100644
--- a/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/80_multiple_indices.yml
+++ b/modules/runtime-fields-common/src/yamlRestTest/resources/rest-api-spec/test/runtime_fields/80_multiple_indices.yml
@@ -12,7 +12,7 @@ setup:
               day_of_week:
                 type: keyword
                 script: |
-                  emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));
+                  emit(doc['timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));
               tomorrow:
                 type: date
                 script:
diff --git a/muted-tests.yml b/muted-tests.yml
index 7830bb09670a..8d445ab0d5c1 100644
--- a/muted-tests.yml
+++ b/muted-tests.yml
@@ -1,25 +1,10 @@
 tests:
-- class: "org.elasticsearch.xpack.textstructure.structurefinder.TimestampFormatFinderTests"
-  issue: "https://github.com/elastic/elasticsearch/issues/108855"
-  method: "testGuessIsDayFirstFromLocale"
-- class: "org.elasticsearch.test.rest.ClientYamlTestSuiteIT"
-  issue: "https://github.com/elastic/elasticsearch/issues/108857"
-  method: "test {yaml=search/180_locale_dependent_mapping/Test Index and Search locale dependent mappings / dates}"
 - class: "org.elasticsearch.upgrades.SearchStatesIT"
   issue: "https://github.com/elastic/elasticsearch/issues/108991"
   method: "testCanMatch"
 - class: "org.elasticsearch.upgrades.MlTrainedModelsUpgradeIT"
   issue: "https://github.com/elastic/elasticsearch/issues/108993"
   method: "testTrainedModelInference"
-- class: "org.elasticsearch.xpack.security.CoreWithSecurityClientYamlTestSuiteIT"
-  issue: "https://github.com/elastic/elasticsearch/issues/109188"
-  method: "test {yaml=search/180_locale_dependent_mapping/Test Index and Search locale dependent mappings / dates}"
-- class: "org.elasticsearch.xpack.esql.qa.mixed.EsqlClientYamlIT"
-  issue: "https://github.com/elastic/elasticsearch/issues/109189"
-  method: "test {p0=esql/70_locale/Date format with Italian locale}"
-- class: "org.elasticsearch.xpack.test.rest.XPackRestIT"
-  issue: "https://github.com/elastic/elasticsearch/issues/109200"
-  method: "test {p0=esql/70_locale/Date format with Italian locale}"
 - class: org.elasticsearch.smoketest.DocsClientYamlTestSuiteIT
   method: test {yaml=reference/esql/esql-async-query-api/line_17}
   issue: https://github.com/elastic/elasticsearch/issues/109260
diff --git a/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml b/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml
index e35282bb6bfd..05d90d582e7f 100644
--- a/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml
+++ b/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml
@@ -13,7 +13,7 @@ setup:
                 day_of_week:
                   type: keyword
                   script:
-                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
   - do:
       bulk:
         refresh: true
diff --git a/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml b/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml
index 58462786f9a2..1c1a39a7bc1a 100644
--- a/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml
+++ b/qa/ccs-common-rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml
@@ -9,7 +9,7 @@ setup:
                 day_of_week:
                   type: keyword
                   script:
-                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
   - do:
       bulk:
         refresh: true
diff --git a/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search/180_locale_dependent_mapping.yml b/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search/180_locale_dependent_mapping.yml
index c4815304e079..7c345b7d4d3a 100644
--- a/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search/180_locale_dependent_mapping.yml
+++ b/rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/search/180_locale_dependent_mapping.yml
@@ -11,26 +11,26 @@
                       date_field:
                           type: date
                           format: "E, d MMM yyyy HH:mm:ss Z"
-                          locale: "de"
+                          locale: "fr"
   - do:
       bulk:
           refresh: true
           body:
               - '{"index": {"_index": "test_index", "_id": "1"}}'
-              - '{"date_field": "Mi, 06 Dez 2000 02:55:00 -0800"}'
+              - '{"date_field": "mer., 6 déc. 2000 02:55:00 -0800"}'
               - '{"index": {"_index": "test_index", "_id": "2"}}'
-              - '{"date_field": "Do, 07 Dez 2000 02:55:00 -0800"}'
+              - '{"date_field": "jeu., 7 déc. 2000 02:55:00 -0800"}'
 
   - do:
       search:
           rest_total_hits_as_int: true
           index: test_index
-          body: {"query" : {"range" : {"date_field" : {"gte": "Di, 05 Dez 2000 02:55:00 -0800", "lte": "Do, 07 Dez 2000 00:00:00 -0800"}}}}
+          body: {"query" : {"range" : {"date_field" : {"gte": "mar., 5 déc. 2000 02:55:00 -0800", "lte": "jeu., 7 déc. 2000 00:00:00 -0800"}}}}
   - match: { hits.total: 1 }
 
   - do:
       search:
           rest_total_hits_as_int: true
           index: test_index
-          body: {"query" : {"range" : {"date_field" : {"gte": "Di, 05 Dez 2000 02:55:00 -0800", "lte": "Fr, 08 Dez 2000 00:00:00 -0800"}}}}
+          body: {"query" : {"range" : {"date_field" : {"gte": "mar., 5 déc. 2000 02:55:00 -0800", "lte": "ven., 8 déc. 2000 00:00:00 -0800"}}}}
   - match: { hits.total: 2 }
diff --git a/server/src/internalClusterTest/java/org/elasticsearch/search/query/SearchQueryIT.java b/server/src/internalClusterTest/java/org/elasticsearch/search/query/SearchQueryIT.java
index 384395bcb78e..0a30de1bb374 100644
--- a/server/src/internalClusterTest/java/org/elasticsearch/search/query/SearchQueryIT.java
+++ b/server/src/internalClusterTest/java/org/elasticsearch/search/query/SearchQueryIT.java
@@ -1629,14 +1629,8 @@ public class SearchQueryIT extends ESIntegTestCase {
      * Test range with a custom locale, e.g. "de" in this case. Documents here mention the day of week
      * as "Mi" for "Mittwoch (Wednesday" and "Do" for "Donnerstag (Thursday)" and the month in the query
      * as "Dez" for "Dezember (December)".
-     * Note: this test currently needs the JVM arg `-Djava.locale.providers=SPI,COMPAT` to be set.
-     * When running with gradle this is done implicitly through the BuildPlugin, but when running from
-     * an IDE this might need to be set manually in the run configuration. See also CONTRIBUTING.md section
-     * on "Configuring IDEs And Running Tests".
      */
     public void testRangeQueryWithLocaleMapping() throws Exception {
-        assert ("SPI,COMPAT".equals(System.getProperty("java.locale.providers"))) : "`-Djava.locale.providers=SPI,COMPAT` needs to be set";
-
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -1644,7 +1638,7 @@ public class SearchQueryIT extends ESIntegTestCase {
                     .startObject("date_field")
                     .field("type", "date")
                     .field("format", "E, d MMM yyyy HH:mm:ss Z")
-                    .field("locale", "de")
+                    .field("locale", "fr")
                     .endObject()
                     .endObject()
                     .endObject()
@@ -1653,19 +1647,19 @@ public class SearchQueryIT extends ESIntegTestCase {
 
         indexRandom(
             true,
-            prepareIndex("test").setId("1").setSource("date_field", "Mi, 06 Dez 2000 02:55:00 -0800"),
-            prepareIndex("test").setId("2").setSource("date_field", "Do, 07 Dez 2000 02:55:00 -0800")
+            prepareIndex("test").setId("1").setSource("date_field", "mer., 6 déc. 2000 02:55:00 -0800"),
+            prepareIndex("test").setId("2").setSource("date_field", "jeu., 7 déc. 2000 02:55:00 -0800")
         );
 
         assertHitCount(
             prepareSearch("test").setQuery(
-                QueryBuilders.rangeQuery("date_field").gte("Di, 05 Dez 2000 02:55:00 -0800").lte("Do, 07 Dez 2000 00:00:00 -0800")
+                QueryBuilders.rangeQuery("date_field").gte("mar., 5 déc. 2000 02:55:00 -0800").lte("jeu., 7 déc. 2000 00:00:00 -0800")
             ),
             1L
         );
         assertHitCount(
             prepareSearch("test").setQuery(
-                QueryBuilders.rangeQuery("date_field").gte("Di, 05 Dez 2000 02:55:00 -0800").lte("Fr, 08 Dez 2000 00:00:00 -0800")
+                QueryBuilders.rangeQuery("date_field").gte("mar., 5 déc. 2000 02:55:00 -0800").lte("ven., 8 déc. 2000 00:00:00 -0800")
             ),
             2L
         );
diff --git a/server/src/test/java/org/elasticsearch/action/admin/indices/template/reservedstate/ReservedComposableIndexTemplateActionTests.java b/server/src/test/java/org/elasticsearch/action/admin/indices/template/reservedstate/ReservedComposableIndexTemplateActionTests.java
index 32a74fef6120..e0d27bf3dc49 100644
--- a/server/src/test/java/org/elasticsearch/action/admin/indices/template/reservedstate/ReservedComposableIndexTemplateActionTests.java
+++ b/server/src/test/java/org/elasticsearch/action/admin/indices/template/reservedstate/ReservedComposableIndexTemplateActionTests.java
@@ -270,7 +270,7 @@ public class ReservedComposableIndexTemplateActionTests extends ESTestCase {
                         "day_of_week": {
                           "type": "keyword",
                           "script": {
-                            "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                            "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
                           }
                         }
                       }
@@ -294,7 +294,7 @@ public class ReservedComposableIndexTemplateActionTests extends ESTestCase {
                         "day_of_week": {
                           "type": "keyword",
                           "script": {
-                            "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                            "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
                           }
                         }
                       }
diff --git a/server/src/test/java/org/elasticsearch/common/time/DateFormattersTests.java b/server/src/test/java/org/elasticsearch/common/time/DateFormattersTests.java
index a9b7cb74e548..676243147748 100644
--- a/server/src/test/java/org/elasticsearch/common/time/DateFormattersTests.java
+++ b/server/src/test/java/org/elasticsearch/common/time/DateFormattersTests.java
@@ -880,11 +880,11 @@ public class DateFormattersTests extends ESTestCase {
 
     public void testCustomLocales() {
         // also ensure that locale based dates are the same
-        DateFormatter formatter = DateFormatter.forPattern("E, d MMM yyyy HH:mm:ss Z").withLocale(LocaleUtils.parse("de"));
-        assertParses("Di, 05 Dez 2000 02:55:00 -0800", formatter);
-        assertParses("Mi, 06 Dez 2000 02:55:00 -0800", formatter);
-        assertParses("Do, 07 Dez 2000 00:00:00 -0800", formatter);
-        assertParses("Fr, 08 Dez 2000 00:00:00 -0800", formatter);
+        DateFormatter formatter = DateFormatter.forPattern("E, d MMM yyyy HH:mm:ss Z").withLocale(LocaleUtils.parse("fr"));
+        assertParses("mar., 5 déc. 2000 02:55:00 -0800", formatter);
+        assertParses("mer., 6 déc. 2000 02:55:00 -0800", formatter);
+        assertParses("jeu., 7 déc. 2000 00:00:00 -0800", formatter);
+        assertParses("ven., 8 déc. 2000 00:00:00 -0800", formatter);
     }
 
     public void testFormatsValidParsing() {
diff --git a/server/src/test/java/org/elasticsearch/index/mapper/DateFieldMapperTests.java b/server/src/test/java/org/elasticsearch/index/mapper/DateFieldMapperTests.java
index 9cfdb2c46a29..4efdd43b5cd7 100644
--- a/server/src/test/java/org/elasticsearch/index/mapper/DateFieldMapperTests.java
+++ b/server/src/test/java/org/elasticsearch/index/mapper/DateFieldMapperTests.java
@@ -183,10 +183,10 @@ public class DateFieldMapperTests extends MapperTestCase {
 
     public void testChangeLocale() throws IOException {
         DocumentMapper mapper = createDocumentMapper(
-            fieldMapping(b -> b.field("type", "date").field("format", "E, d MMM yyyy HH:mm:ss Z").field("locale", "de"))
+            fieldMapping(b -> b.field("type", "date").field("format", "E, d MMM yyyy HH:mm:ss Z").field("locale", "fr"))
         );
 
-        mapper.parse(source(b -> b.field("field", "Mi, 06 Dez 2000 02:55:00 -0800")));
+        mapper.parse(source(b -> b.field("field", "mer., 6 déc. 2000 02:55:00 -0800")));
     }
 
     public void testNullValue() throws IOException {
diff --git a/x-pack/plugin/core/src/main/java/org/elasticsearch/license/LicenseUtils.java b/x-pack/plugin/core/src/main/java/org/elasticsearch/license/LicenseUtils.java
index 42f0ddb3f523..b27c1bb9d449 100644
--- a/x-pack/plugin/core/src/main/java/org/elasticsearch/license/LicenseUtils.java
+++ b/x-pack/plugin/core/src/main/java/org/elasticsearch/license/LicenseUtils.java
@@ -25,7 +25,7 @@ import java.util.concurrent.TimeUnit;
 public class LicenseUtils {
 
     public static final String EXPIRED_FEATURE_METADATA = "es.license.expired.feature";
-    public static final DateFormatter DATE_FORMATTER = DateFormatter.forPattern("EEEE, MMMM dd, yyyy");
+    public static final DateFormatter DATE_FORMATTER = DateFormatter.forPattern("EEEE, MMMM dd, yyyy").withLocale(Locale.ENGLISH);
 
     /**
      * Exception to be thrown when a feature action requires a valid license, but license
diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/license/ClusterStateLicenseServiceTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/license/ClusterStateLicenseServiceTests.java
index c0c7c5c59d24..aaadecef6021 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/license/ClusterStateLicenseServiceTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/license/ClusterStateLicenseServiceTests.java
@@ -65,11 +65,6 @@ import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
-/**
- * Due to changes in JDK9 where locale data is used from CLDR, the licence message will differ in jdk 8 and jdk9+
- * https://openjdk.java.net/jeps/252
- * We run ES with -Djava.locale.providers=SPI,COMPAT and same option has to be applied when running this test from IDE
- */
 public class ClusterStateLicenseServiceTests extends ESTestCase {
 
     // must use member mock for generic
diff --git a/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml b/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml
index dc9fd1e475cc..e49264d76d5e 100644
--- a/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml
+++ b/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/10_basic.yml
@@ -13,7 +13,7 @@ setup:
                 day_of_week:
                   type: keyword
                   script:
-                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
   - do:
       bulk:
         refresh: true
diff --git a/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml b/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml
index 58462786f9a2..1c1a39a7bc1a 100644
--- a/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml
+++ b/x-pack/plugin/eql/qa/rest/src/yamlRestTest/resources/rest-api-spec/test/eql/20_runtime_mappings.yml
@@ -9,7 +9,7 @@ setup:
                 day_of_week:
                   type: keyword
                   script:
-                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT))"
+                    source: "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH))"
   - do:
       bulk:
         refresh: true
diff --git a/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/expression/function/scalar/datetime/DateTimeFormatProcessorTests.java b/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/expression/function/scalar/datetime/DateTimeFormatProcessorTests.java
index 997447c525e4..5294fa05dfde 100644
--- a/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/expression/function/scalar/datetime/DateTimeFormatProcessorTests.java
+++ b/x-pack/plugin/sql/src/test/java/org/elasticsearch/xpack/sql/expression/function/scalar/datetime/DateTimeFormatProcessorTests.java
@@ -157,12 +157,12 @@ public class DateTimeFormatProcessorTests extends AbstractSqlWireSerializingTest
             new DateTimeFormat(Source.EMPTY, dateTime, l("YYYY-MM-dd HH:mm:ss.SSSSSSSS"), zoneId).makePipe().asProcessor().process(null)
         );
         assertEquals("+1000", new DateTimeFormat(Source.EMPTY, dateTime, l("Z"), zoneId).makePipe().asProcessor().process(null));
-        assertEquals("Etc/GMT-10", new DateTimeFormat(Source.EMPTY, dateTime, l("z"), zoneId).makePipe().asProcessor().process(null));
+        assertEquals("GMT+10:00", new DateTimeFormat(Source.EMPTY, dateTime, l("z"), zoneId).makePipe().asProcessor().process(null));
         assertEquals("Etc/GMT-10", new DateTimeFormat(Source.EMPTY, dateTime, l("VV"), zoneId).makePipe().asProcessor().process(null));
 
         zoneId = ZoneId.of("America/Sao_Paulo");
         assertEquals("-0300", new DateTimeFormat(Source.EMPTY, dateTime, l("Z"), zoneId).makePipe().asProcessor().process(null));
-        assertEquals("BRT", new DateTimeFormat(Source.EMPTY, dateTime, l("z"), zoneId).makePipe().asProcessor().process(null));
+        assertEquals("GMT-03:00", new DateTimeFormat(Source.EMPTY, dateTime, l("z"), zoneId).makePipe().asProcessor().process(null));
         assertEquals(
             "America/Sao_Paulo",
             new DateTimeFormat(Source.EMPTY, dateTime, l("VV"), zoneId).makePipe().asProcessor().process(null)
@@ -208,7 +208,7 @@ public class DateTimeFormatProcessorTests extends AbstractSqlWireSerializingTest
         );
         assertEquals("Z", new Format(Source.EMPTY, dateTime, l("Z"), zoneId).makePipe().asProcessor().process(null));
         assertEquals("+10", new Format(Source.EMPTY, dateTime, l("z"), zoneId).makePipe().asProcessor().process(null));
-        assertEquals("Etc/GMT-10", new Format(Source.EMPTY, dateTime, l("K"), zoneId).makePipe().asProcessor().process(null));
+        assertEquals("GMT+10:00", new Format(Source.EMPTY, dateTime, l("K"), zoneId).makePipe().asProcessor().process(null));
 
         assertEquals("1", new Format(Source.EMPTY, dateTime, l("F"), zoneId).makePipe().asProcessor().process(null));
         assertEquals("12", new Format(Source.EMPTY, dateTime, l("FF"), zoneId).makePipe().asProcessor().process(null));
diff --git a/x-pack/qa/runtime-fields/with-security/src/javaRestTest/java/org/elasticsearch/xpack/security/PermissionsIT.java b/x-pack/qa/runtime-fields/with-security/src/javaRestTest/java/org/elasticsearch/xpack/security/PermissionsIT.java
index e938e61734ba..a76317d42e19 100644
--- a/x-pack/qa/runtime-fields/with-security/src/javaRestTest/java/org/elasticsearch/xpack/security/PermissionsIT.java
+++ b/x-pack/qa/runtime-fields/with-security/src/javaRestTest/java/org/elasticsearch/xpack/security/PermissionsIT.java
@@ -290,7 +290,7 @@ public class PermissionsIT extends ESRestTestCase {
         painlessExecute.setJsonEntity("""
             {
               "script": {
-                "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ROOT));"
+                "source": "emit(doc['@timestamp'].value.dayOfWeekEnum.getDisplayName(TextStyle.FULL, Locale.ENGLISH));"
               },
               "context": "keyword_field",
               "context_setup": {