diff --git a/core/api/current.txt b/core/api/current.txt
index 70e33dfad778c..e2f388a99ab34 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -35359,7 +35359,7 @@ package android.provider {
     field @Deprecated public static final String BLUETOOTH_ON = "bluetooth_on";
     field public static final android.net.Uri CONTENT_URI;
     field @Deprecated public static final String DATA_ROAMING = "data_roaming";
-    field public static final String DATE_FORMAT = "date_format";
+    field @Deprecated public static final String DATE_FORMAT = "date_format";
     field @Deprecated public static final String DEBUG_APP = "debug_app";
     field public static final android.net.Uri DEFAULT_ALARM_ALERT_URI;
     field public static final android.net.Uri DEFAULT_NOTIFICATION_URI;
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 13819550d7e24..a4f9ddc256580 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -4666,11 +4666,9 @@ public final class Settings {
         public static final String TIME_12_24 = "time_12_24";
 
         /**
-         * Date format string
-         *   mm/dd/yyyy
-         *   dd/mm/yyyy
-         *   yyyy/mm/dd
+         * @deprecated No longer used. Use {@link #TIME_12_24} instead.
          */
+        @Deprecated
         @Readable
         public static final String DATE_FORMAT = "date_format";
 
diff --git a/core/proto/android/providers/settings/system.proto b/core/proto/android/providers/settings/system.proto
index b723b5307bc11..f8b5b233c6072 100644
--- a/core/proto/android/providers/settings/system.proto
+++ b/core/proto/android/providers/settings/system.proto
@@ -52,7 +52,8 @@ message SystemSettingsProto {
     }
     optional Bluetooth bluetooth = 4;
 
-    optional SettingProto date_format = 5 [ (android.privacy).dest = DEST_AUTOMATIC ];
+    reserved 5; // date_format is not used
+
     optional SettingProto display_color_mode = 6 [ (android.privacy).dest = DEST_AUTOMATIC ];
 
     message DevOptions {
diff --git a/packages/SettingsProvider/src/android/provider/settings/backup/SystemSettings.java b/packages/SettingsProvider/src/android/provider/settings/backup/SystemSettings.java
index 30fd12b6105a8..0fe4efefc2cb8 100644
--- a/packages/SettingsProvider/src/android/provider/settings/backup/SystemSettings.java
+++ b/packages/SettingsProvider/src/android/provider/settings/backup/SystemSettings.java
@@ -56,7 +56,6 @@ public class SystemSettings {
         Settings.System.AUTO_TIME,                  // moved to global
         Settings.System.AUTO_TIME_ZONE,             // moved to global
         Settings.System.TIME_12_24,
-        Settings.System.DATE_FORMAT,
         Settings.System.DTMF_TONE_WHEN_DIALING,
         Settings.System.DTMF_TONE_TYPE_WHEN_DIALING,
         Settings.System.HEARING_AID,
diff --git a/packages/SettingsProvider/src/android/provider/settings/validators/SettingsValidators.java b/packages/SettingsProvider/src/android/provider/settings/validators/SettingsValidators.java
index 97e1d6848af66..223cc51a5390b 100644
--- a/packages/SettingsProvider/src/android/provider/settings/validators/SettingsValidators.java
+++ b/packages/SettingsProvider/src/android/provider/settings/validators/SettingsValidators.java
@@ -25,7 +25,6 @@ import android.text.TextUtils;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-import java.text.SimpleDateFormat;
 import java.util.Locale;
 
 /**
@@ -192,18 +191,6 @@ public class SettingsValidators {
 
     public static final Validator TILE_LIST_VALIDATOR = new TileListValidator();
 
-    static final Validator DATE_FORMAT_VALIDATOR = value -> {
-        try {
-            if (value == null) {
-                return true;
-            }
-            new SimpleDateFormat(value);
-            return true;
-        } catch (IllegalArgumentException | NullPointerException e) {
-            return false;
-        }
-    };
-
     static final Validator COLON_SEPARATED_COMPONENT_LIST_VALIDATOR =
             new ComponentNameListValidator(":");
 
diff --git a/packages/SettingsProvider/src/android/provider/settings/validators/SystemSettingsValidators.java b/packages/SettingsProvider/src/android/provider/settings/validators/SystemSettingsValidators.java
index ebf811f63d3ab..462c3a5bba035 100644
--- a/packages/SettingsProvider/src/android/provider/settings/validators/SystemSettingsValidators.java
+++ b/packages/SettingsProvider/src/android/provider/settings/validators/SystemSettingsValidators.java
@@ -19,7 +19,6 @@ package android.provider.settings.validators;
 import static android.provider.settings.validators.SettingsValidators.ANY_STRING_VALIDATOR;
 import static android.provider.settings.validators.SettingsValidators.BOOLEAN_VALIDATOR;
 import static android.provider.settings.validators.SettingsValidators.COMPONENT_NAME_VALIDATOR;
-import static android.provider.settings.validators.SettingsValidators.DATE_FORMAT_VALIDATOR;
 import static android.provider.settings.validators.SettingsValidators.LENIENT_IP_ADDRESS_VALIDATOR;
 import static android.provider.settings.validators.SettingsValidators.NON_NEGATIVE_INTEGER_VALIDATOR;
 import static android.provider.settings.validators.SettingsValidators.URI_VALIDATOR;
@@ -146,7 +145,6 @@ public class SystemSettingsValidators {
                 });
         VALIDATORS.put(
                 System.TIME_12_24, new DiscreteValueValidator(new String[] {"12", "24", null}));
-        VALIDATORS.put(System.DATE_FORMAT, DATE_FORMAT_VALIDATOR);
         VALIDATORS.put(System.SETUP_WIZARD_HAS_RUN, BOOLEAN_VALIDATOR);
         VALIDATORS.put(System.ACCELEROMETER_ROTATION, BOOLEAN_VALIDATOR);
         VALIDATORS.put(System.USER_ROTATION, new InclusiveIntegerRangeValidator(0, 3));
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProtoDumpUtil.java b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProtoDumpUtil.java
index 2a50be7a0d182..b5dbf22187bf9 100644
--- a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProtoDumpUtil.java
+++ b/packages/SettingsProvider/src/com/android/providers/settings/SettingsProtoDumpUtil.java
@@ -2704,9 +2704,6 @@ class SettingsProtoDumpUtil {
                 SystemSettingsProto.Bluetooth.DISCOVERABILITY_TIMEOUT_SECS);
         p.end(bluetoothToken);
 
-        dumpSetting(s, p,
-                Settings.System.DATE_FORMAT,
-                SystemSettingsProto.DATE_FORMAT);
         dumpSetting(s, p,
                 Settings.System.DISPLAY_COLOR_MODE,
                 SystemSettingsProto.DISPLAY_COLOR_MODE);
diff --git a/packages/SettingsProvider/test/src/android/provider/settings/validators/SettingsValidatorsTest.java b/packages/SettingsProvider/test/src/android/provider/settings/validators/SettingsValidatorsTest.java
index e5d148cb213a4..865f431183c62 100644
--- a/packages/SettingsProvider/test/src/android/provider/settings/validators/SettingsValidatorsTest.java
+++ b/packages/SettingsProvider/test/src/android/provider/settings/validators/SettingsValidatorsTest.java
@@ -219,11 +219,6 @@ public class SettingsValidatorsTest {
         assertFalse(v.validate(null));
     }
 
-    @Test
-    public void dateFormatValidator_onNullValue_returnsTrue() {
-        assertTrue(SettingsValidators.DATE_FORMAT_VALIDATOR.validate(null));
-    }
-
     @Test
     public void testJSONObjectValidator() throws JSONException {
         Validator v = SettingsValidators.JSON_OBJECT_VALIDATOR;