diff --git a/core/dbt/materializations/incremental/microbatch.py b/core/dbt/materializations/incremental/microbatch.py
index 6de6945704c..370082461e6 100644
--- a/core/dbt/materializations/incremental/microbatch.py
+++ b/core/dbt/materializations/incremental/microbatch.py
@@ -194,13 +194,21 @@ def truncate_timestamp(timestamp: datetime, batch_size: BatchSize) -> datetime:
 
     @staticmethod
     def batch_id(start_time: datetime, batch_size: BatchSize) -> str:
-        return MicrobatchBuilder.format_batch_start(start_time, batch_size).replace("-", "")
+        return MicrobatchBuilder.format_batch_start(start_time, batch_size)
 
     @staticmethod
     def format_batch_start(batch_start: datetime, batch_size: BatchSize) -> str:
-        return str(
-            batch_start.date() if (batch_start and batch_size != BatchSize.hour) else batch_start
-        )
+        """Format the passed in datetime based on the batch_size.
+
+        2024-09-17 16:06:00 + Batchsize.day  -> 20240917
+        2024-09-17 16:06:00 + Batchsize.hour -> 20240917T16
+        """
+        # If we want a date only
+        if batch_size != BatchSize.hour:
+            return batch_start.strftime("%Y%m%d")
+
+        # If we want date + time
+        return batch_start.strftime("%Y%m%dT%H")
 
     @staticmethod
     def ceiling_timestamp(timestamp: datetime, batch_size: BatchSize) -> datetime:
diff --git a/tests/unit/materializations/incremental/test_microbatch.py b/tests/unit/materializations/incremental/test_microbatch.py
index 3d827a79975..ed5415c0f0b 100644
--- a/tests/unit/materializations/incremental/test_microbatch.py
+++ b/tests/unit/materializations/incremental/test_microbatch.py
@@ -602,13 +602,27 @@ def test_offset_timestamp(self, timestamp, batch_size, offset, expected_timestam
     def test_truncate_timestamp(self, timestamp, batch_size, expected_timestamp):
         assert MicrobatchBuilder.truncate_timestamp(timestamp, batch_size) == expected_timestamp
 
+    @pytest.mark.parametrize(
+        "batch_size,start_time,expected_formatted_start_time",
+        [
+            (BatchSize.year, None, ""),
+            (BatchSize.year, datetime(2020, 1, 1, 1), "20200101"),
+            (BatchSize.month, datetime(2020, 1, 1, 1), "20200101"),
+            (BatchSize.day, datetime(2020, 1, 1, 1), "20200101"),
+            (BatchSize.hour, datetime(2020, 1, 1, 1), "20200101T01"),
+        ],
+    )
+    def test_batch_id(self, batch_size, start_time, expected_formatted_start_time):
+        assert MicrobatchBuilder.batch_id(start_time, batch_size) == expected_formatted_start_time
+
     @pytest.mark.parametrize(
         "batch_size,batch_start,expected_formatted_batch_start",
         [
-            (BatchSize.year, datetime(2020, 1, 1, 1), "2020-01-01"),
-            (BatchSize.month, datetime(2020, 1, 1, 1), "2020-01-01"),
-            (BatchSize.day, datetime(2020, 1, 1, 1), "2020-01-01"),
-            (BatchSize.hour, datetime(2020, 1, 1, 1), "2020-01-01 01:00:00"),
+            (BatchSize.year, None, ""),
+            (BatchSize.year, datetime(2020, 1, 1, 1), "20200101"),
+            (BatchSize.month, datetime(2020, 1, 1, 1), "20200101"),
+            (BatchSize.day, datetime(2020, 1, 1, 1), "20200101"),
+            (BatchSize.hour, datetime(2020, 1, 1, 1), "20200101T01"),
         ],
     )
     def test_format_batch_start(self, batch_size, batch_start, expected_formatted_batch_start):