diff --git a/alerting/src/main/kotlin/org/opensearch/alerting/InputService.kt b/alerting/src/main/kotlin/org/opensearch/alerting/InputService.kt
index 557c6db88..ccea577bc 100644
--- a/alerting/src/main/kotlin/org/opensearch/alerting/InputService.kt
+++ b/alerting/src/main/kotlin/org/opensearch/alerting/InputService.kt
@@ -306,8 +306,10 @@ class InputService(
                                 resolvedIndexes.add(indexMetadata.index.name)
                                 includePrevious = false // No need to include previous anymore
                             } else if (
-                                includePrevious && i > 0 && sortedIndices[i - 1].creationDate <
-                                resolveStartTimeOfQueryTimeRange.toEpochMilli()
+                                includePrevious && (
+                                    i == sortedIndices.lastIndex ||
+                                        sortedIndices[i + 1].creationDate >= resolveStartTimeOfQueryTimeRange.toEpochMilli()
+                                    )
                             ) {
                                 // Include the index immediately before the timestamp
                                 resolvedIndexes.add(indexMetadata.index.name)
@@ -315,6 +317,7 @@ class InputService(
                             }
                         }
                     } else {
+                        // add alias without optimizing for resolve indices
                         resolvedIndexes.add(it)
                     }
                 } else {
diff --git a/alerting/src/test/kotlin/org/opensearch/alerting/AlertingRestTestCase.kt b/alerting/src/test/kotlin/org/opensearch/alerting/AlertingRestTestCase.kt
index bea6531e5..4ae4cc923 100644
--- a/alerting/src/test/kotlin/org/opensearch/alerting/AlertingRestTestCase.kt
+++ b/alerting/src/test/kotlin/org/opensearch/alerting/AlertingRestTestCase.kt
@@ -1241,6 +1241,25 @@ abstract class AlertingRestTestCase : ODFERestTestCase() {
         }
     }
 
+    protected fun insertSampleTimeSerializedDataWithTime(
+        index: String,
+        data: List<String>,
+        time: ZonedDateTime? = ZonedDateTime.now().truncatedTo(ChronoUnit.MILLIS),
+    ) {
+        data.forEachIndexed { i, value ->
+            val testTime = DateTimeFormatter.ISO_OFFSET_DATE_TIME.format(time)
+            val testDoc = """
+                {
+                  "test_strict_date_time": "$testTime",
+                  "test_field": "$value",
+                   "number": "$i"
+                }
+            """.trimIndent()
+            // Indexing documents with deterministic doc id to allow for easy selected deletion during testing
+            indexDoc(index, (i + 1).toString(), testDoc)
+        }
+    }
+
     protected fun deleteDataWithDocIds(index: String, docIds: List<String>) {
         docIds.forEach {
             deleteDoc(index, it)
diff --git a/alerting/src/test/kotlin/org/opensearch/alerting/MonitorRunnerServiceIT.kt b/alerting/src/test/kotlin/org/opensearch/alerting/MonitorRunnerServiceIT.kt
index 98c41e499..c017bf4a2 100644
--- a/alerting/src/test/kotlin/org/opensearch/alerting/MonitorRunnerServiceIT.kt
+++ b/alerting/src/test/kotlin/org/opensearch/alerting/MonitorRunnerServiceIT.kt
@@ -1191,16 +1191,10 @@ class MonitorRunnerServiceIT : AlertingRestTestCase() {
         assertEquals("Incorrect search result", 2, buckets.size)
     }
 
-    fun `test execute bucket-level monitor with alias optimization - indices not skipped`() {
-        val testIndex = createTestIndex()
-        insertSampleTimeSerializedDataCurrentTime(
-            testIndex,
-            listOf(
-                "test_value_3",
-                "test_value_4", // adding duplicate to verify aggregation
-                "test_value_5"
-            )
-        )
+    fun `test execute bucket-level monitor with alias optimization - indices not skipped from query`() {
+        val skipIndex = createTestIndex("to_skip_index")
+        val previousIndex = createTestIndex("to_include_index")
+
         val indexMapping = """
                 "properties" : {
                   "test_strict_date_time" : { "type" : "date", "format" : "strict_date_time" },
@@ -1218,7 +1212,24 @@ class MonitorRunnerServiceIT : AlertingRestTestCase() {
                 "test_value_2"
             )
         )
-        addIndexToAlias(testIndex, aliasName)
+        insertSampleTimeSerializedDataWithTime(
+            previousIndex,
+            listOf(
+                "test_value_3",
+                "test_value_4",
+                "test_value_5"
+            )
+        )
+        insertSampleTimeSerializedDataWithTime(
+            skipIndex,
+            listOf(
+                "test_value_6",
+                "test_value_7",
+                "test_value_8"
+            )
+        )
+        addIndexToAlias(previousIndex, aliasName)
+        addIndexToAlias(skipIndex, aliasName)
         val query = QueryBuilders.rangeQuery("test_strict_date_time")
             .gt("{{period_end}}||-10s")
             .lte("{{period_end}}")
@@ -1251,18 +1262,30 @@ class MonitorRunnerServiceIT : AlertingRestTestCase() {
         val searchResult = (output.objectMap("input_results")["results"] as List<Map<String, Any>>).first()
         @Suppress("UNCHECKED_CAST")
         val buckets = searchResult.stringMap("aggregations")?.stringMap("composite_agg")?.get("buckets") as List<Map<String, Any>>
-        assertEquals("Incorrect search result", 5, buckets.size)
+        Assert.assertEquals(buckets.size, 8)
     }
 
     fun `test execute bucket-level monitor with alias optimization - indices skipped from query`() {
-        val testIndex = createTestIndex()
-        insertSampleTimeSerializedDataCurrentTime(
-            testIndex,
+        val skipIndex = createTestIndex("to_skip_index")
+        Thread.sleep(10000)
+        val previousIndex = createTestIndex("to_include_index")
+        insertSampleTimeSerializedDataWithTime(
+            previousIndex,
             listOf(
-                "test_value_1",
-                "test_value_1", // adding duplicate to verify aggregation
-                "test_value_2"
-            )
+                "test_value_3",
+                "test_value_4",
+                "test_value_5"
+            ),
+            ZonedDateTime.now().truncatedTo(ChronoUnit.MILLIS).plusSeconds(10)
+        )
+        insertSampleTimeSerializedDataWithTime(
+            skipIndex,
+            listOf(
+                "test_value_6",
+                "test_value_7",
+                "test_value_8"
+            ),
+            ZonedDateTime.now().truncatedTo(ChronoUnit.MILLIS).plusSeconds(10)
         )
         Thread.sleep(10000)
         val indexMapping = """
@@ -1282,7 +1305,8 @@ class MonitorRunnerServiceIT : AlertingRestTestCase() {
                 "test_value_2"
             )
         )
-        addIndexToAlias(testIndex, aliasName)
+        addIndexToAlias(previousIndex, aliasName)
+        addIndexToAlias(skipIndex, aliasName)
         val query = QueryBuilders.rangeQuery("test_strict_date_time")
             .gt("{{period_end}}||-10s")
             .lte("{{period_end}}")
@@ -1315,7 +1339,7 @@ class MonitorRunnerServiceIT : AlertingRestTestCase() {
         val searchResult = (output.objectMap("input_results")["results"] as List<Map<String, Any>>).first()
         @Suppress("UNCHECKED_CAST")
         val buckets = searchResult.stringMap("aggregations")?.stringMap("composite_agg")?.get("buckets") as List<Map<String, Any>>
-        Assert.assertTrue(buckets.size <= 2)
+        Assert.assertTrue(buckets.size <= 5)
     }
 
     fun `test execute bucket-level monitor returns search result with multi term agg`() {