diff --git a/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java b/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java
index 54516007d32a..c838cc70a3c5 100644
--- a/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java
+++ b/common/src/java/org/apache/hadoop/hive/conf/HiveConf.java
@@ -401,9 +401,10 @@ public static enum ConfVars {
         "Turn on ChangeManager, so delete files will go to cmrootdir."),
     REPL_CM_DIR("hive.repl.cmrootdir","/user/${system:user.name}/cmroot/",
         "Root dir for ChangeManager, used for deleted files."),
-    REPL_CM_RETAIN("hive.repl.cm.retain","10d",
-        new TimeValidator(TimeUnit.DAYS),
-        "Time to retain removed files in cmrootdir."),
+    REPL_CM_RETAIN("hive.repl.cm.retain","240h",
+        new TimeValidator(TimeUnit.HOURS),
+        "Time to retain removed files in cmrootdir. A unit-less value is interpreted in hours, "
+            + "matching the metastore counterpart metastore.repl.cm.retain. Default is 240h (10 days)."),
     REPL_CM_ENCRYPTED_DIR("hive.repl.cm.encryptionzone.rootdir", ".cmroot",
             "Root dir for ChangeManager if encryption zones are enabled, used for deleted files."),
     REPL_CM_FALLBACK_NONENCRYPTED_DIR("hive.repl.cm.nonencryptionzone.rootdir",
diff --git a/common/src/test/org/apache/hadoop/hive/conf/TestHiveConf.java b/common/src/test/org/apache/hadoop/hive/conf/TestHiveConf.java
index a9b3c089c3f2..299abd0d44eb 100644
--- a/common/src/test/org/apache/hadoop/hive/conf/TestHiveConf.java
+++ b/common/src/test/org/apache/hadoop/hive/conf/TestHiveConf.java
@@ -124,6 +124,25 @@ public void testUnitFor() throws Exception {
     Assert.assertEquals(TimeUnit.NANOSECONDS, HiveConf.unitFor("nsecs", null));
   }
 
+  @Test
+  public void testReplCmRetainTimeUnit() throws Exception {
+    HiveConf conf = new HiveConf();
+
+    // The default (240h) is 10 days. Guards against accidentally changing the default duration.
+    Assert.assertEquals(10, conf.getTimeVar(ConfVars.REPL_CM_RETAIN, TimeUnit.DAYS));
+    Assert.assertEquals(240, conf.getTimeVar(ConfVars.REPL_CM_RETAIN, TimeUnit.HOURS));
+
+    // A unit-less value is interpreted in hours, matching the metastore counterpart
+    // metastore.repl.cm.retain, which uses a HOURS base unit.
+    Assert.assertEquals(TimeUnit.HOURS, HiveConf.getDefaultTimeUnit(ConfVars.REPL_CM_RETAIN));
+    conf.setVar(ConfVars.REPL_CM_RETAIN, "10");
+    Assert.assertEquals(10, conf.getTimeVar(ConfVars.REPL_CM_RETAIN, TimeUnit.HOURS));
+
+    // An explicit unit suffix is still honoured.
+    conf.setVar(ConfVars.REPL_CM_RETAIN, "10d");
+    Assert.assertEquals(10, conf.getTimeVar(ConfVars.REPL_CM_RETAIN, TimeUnit.DAYS));
+  }
+
   @Test
   public void testToSizeBytes() throws Exception {
     Assert.assertEquals(1L, HiveConf.toSizeBytes("1b"));