diff --git a/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DayTest.java b/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DayTest.java
new file mode 100644
index 0000000..ee5ae98
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/desugar/desugaredlibrary/DayTest.java
@@ -0,0 +1,159 @@
+// Copyright (c) 2024, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.android.tools.r8.desugar.desugaredlibrary;
+
+import static com.android.tools.r8.desugar.desugaredlibrary.test.CompilationSpecification.DEFAULT_SPECIFICATIONS;
+import static com.android.tools.r8.desugar.desugaredlibrary.test.LibraryDesugaringSpecification.JDK8;
+import static com.android.tools.r8.desugar.desugaredlibrary.test.LibraryDesugaringSpecification.getJdk8Jdk11;
+
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestRuntime.CfVm;
+import com.android.tools.r8.desugar.desugaredlibrary.test.CompilationSpecification;
+import com.android.tools.r8.desugar.desugaredlibrary.test.LibraryDesugaringSpecification;
+import com.android.tools.r8.utils.StringUtils;
+import java.time.DayOfWeek;
+import java.time.format.TextStyle;
+import java.util.List;
+import java.util.Locale;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class DayTest extends DesugaredLibraryTestBase {
+  private static final String MISSING_STANDALONE = StringUtils.lines("1", "1", "1234567");
+  // TODO(b/300128109): Wrong SIMPLIFIED_CHINESE narrow day values.
+  private static final String SIMPLIFIED_CHINESE_NARROW_DAY_ISSUE =
+      StringUtils.lines("星期一", "周一", "星星星星星星星");
+
+  private static final String UK_EXPECTED_RESULT_JDK8 =
+      StringUtils.lines("Monday", "Mon", "1234567");
+  private static final String UK_EXPECTED_RESULT = StringUtils.lines("Monday", "Mon", "MTWTFSS");
+
+  private static final String SIMPLIFIED_CHINESE_EXPECTED_RESULT_JDK8 =
+      StringUtils.lines("星期一", "星期一", "一二三四五六日");
+  private static final String SIMPLIFIED_CHINESE_EXPECTED_RESULT =
+      StringUtils.lines("星期一", "周一", "一二三四五六日");
+
+  private final TestParameters parameters;
+  private final LibraryDesugaringSpecification libraryDesugaringSpecification;
+  private final CompilationSpecification compilationSpecification;
+
+  @Parameters(name = "{0}, spec: {1}, {2}")
+  public static List<Object[]> data() {
+    return buildParameters(
+        getTestParameters().withAllRuntimes().withAllApiLevels().build(),
+        getJdk8Jdk11(),
+        DEFAULT_SPECIFICATIONS);
+  }
+
+  public DayTest(
+      TestParameters parameters,
+      LibraryDesugaringSpecification libraryDesugaringSpecification,
+      CompilationSpecification compilationSpecification) {
+    this.parameters = parameters;
+    this.libraryDesugaringSpecification = libraryDesugaringSpecification;
+    this.compilationSpecification = compilationSpecification;
+  }
+
+  private String getUKStandaloneExpectedResult() {
+    if (parameters.isCfRuntime() && parameters.getRuntime().asCf().isOlderThan(CfVm.JDK9)) {
+      return UK_EXPECTED_RESULT_JDK8;
+    }
+    if (parameters.isDexRuntime()
+        && libraryDesugaringSpecification.hasTimeDesugaring(parameters)
+        && libraryDesugaringSpecification == JDK8) {
+      return MISSING_STANDALONE;
+    }
+    return UK_EXPECTED_RESULT;
+  }
+
+  private String getSimplifiedChineseStandaloneExpectedResult() {
+    if (parameters.isCfRuntime() && parameters.getRuntime().asCf().isOlderThan(CfVm.JDK9)) {
+      return SIMPLIFIED_CHINESE_EXPECTED_RESULT_JDK8;
+    }
+    if (parameters.isDexRuntime() && libraryDesugaringSpecification.hasTimeDesugaring(parameters)) {
+      if (libraryDesugaringSpecification == JDK8) {
+        return MISSING_STANDALONE;
+      } else {
+        return SIMPLIFIED_CHINESE_NARROW_DAY_ISSUE;
+      }
+    }
+    return SIMPLIFIED_CHINESE_EXPECTED_RESULT;
+  }
+
+  private String getSimplifiedChineseExpectedResult() {
+    if (parameters.isCfRuntime() && parameters.getRuntime().asCf().isOlderThan(CfVm.JDK9)) {
+      return SIMPLIFIED_CHINESE_EXPECTED_RESULT_JDK8;
+    }
+    if (parameters.isDexRuntime() && libraryDesugaringSpecification.hasTimeDesugaring(parameters)) {
+      return SIMPLIFIED_CHINESE_NARROW_DAY_ISSUE;
+    }
+    return SIMPLIFIED_CHINESE_EXPECTED_RESULT;
+  }
+
+  private String getExpectedResult() {
+    return getUKStandaloneExpectedResult()
+        + UK_EXPECTED_RESULT
+        + getSimplifiedChineseStandaloneExpectedResult()
+        + getSimplifiedChineseExpectedResult();
+  }
+
+  @Test
+  public void testDay() throws Exception {
+    if (parameters.isCfRuntime()) {
+      // TODO(b/300128109): Enable this assert if test fails on Windows. Otherwise remove it.
+      // Assume.assumeFalse("Missing data for Locale SIMPLIFIED_CHINESE on Windows",
+      //     ToolHelper.isWindows());
+      testForJvm(parameters)
+          .addInnerClasses(DayTest.class)
+          .run(parameters.getRuntime(), Main.class)
+          .assertSuccessWithOutput(getExpectedResult());
+      return;
+    }
+    testForDesugaredLibrary(parameters, libraryDesugaringSpecification, compilationSpecification)
+        .addInnerClasses(getClass())
+        .addKeepMainRule(Main.class)
+        .run(parameters.getRuntime(), Main.class)
+        .assertSuccessWithOutput(getExpectedResult());
+  }
+
+  static class Main {
+
+    public static void testStandalone(Locale locale) {
+      System.out.println(DayOfWeek.MONDAY.getDisplayName(TextStyle.FULL_STANDALONE, locale));
+      System.out.println(DayOfWeek.MONDAY.getDisplayName(TextStyle.SHORT_STANDALONE, locale));
+      System.out.println(
+          DayOfWeek.MONDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale)
+              + DayOfWeek.TUESDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale)
+              + DayOfWeek.WEDNESDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale)
+              + DayOfWeek.THURSDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale)
+              + DayOfWeek.FRIDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale)
+              + DayOfWeek.SATURDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale)
+              + DayOfWeek.SUNDAY.getDisplayName(TextStyle.NARROW_STANDALONE, locale));
+    }
+
+    public static void test(Locale locale) {
+      System.out.println(DayOfWeek.MONDAY.getDisplayName(TextStyle.FULL, locale));
+      System.out.println(DayOfWeek.MONDAY.getDisplayName(TextStyle.SHORT, locale));
+      System.out.println(
+          DayOfWeek.MONDAY.getDisplayName(TextStyle.NARROW, locale)
+              + DayOfWeek.TUESDAY.getDisplayName(TextStyle.NARROW, locale)
+              + DayOfWeek.WEDNESDAY.getDisplayName(TextStyle.NARROW, locale)
+              + DayOfWeek.THURSDAY.getDisplayName(TextStyle.NARROW, locale)
+              + DayOfWeek.FRIDAY.getDisplayName(TextStyle.NARROW, locale)
+              + DayOfWeek.SATURDAY.getDisplayName(TextStyle.NARROW, locale)
+              + DayOfWeek.SUNDAY.getDisplayName(TextStyle.NARROW, locale));
+    }
+
+    public static void main(String[] args) {
+      testStandalone(Locale.UK);
+      test(Locale.UK);
+      testStandalone(Locale.SIMPLIFIED_CHINESE);
+      test(Locale.SIMPLIFIED_CHINESE);
+    }
+  }
+}