diff --git a/aeon/dj_pipeline/analysis/block_analysis.py b/aeon/dj_pipeline/analysis/block_analysis.py
index 2880b050..db3934a8 100644
--- a/aeon/dj_pipeline/analysis/block_analysis.py
+++ b/aeon/dj_pipeline/analysis/block_analysis.py
@@ -42,10 +42,18 @@ class Block(dj.Manual):
 
 @schema
 class BlockDetection(dj.Computed):
-    definition = """
+    definition = """  # Detecting new block(s) for each new Chunk
     -> acquisition.Environment
+    ---
+    execution_time=null: datetime
     """
 
+    class IdentifiedBlock(dj.Part):
+        definition = """ # the block(s) identified in this BlockDetection
+        -> master
+        -> Block
+        """
+
     key_source = acquisition.Environment - {"experiment_name": "social0.1-aeon3"}
 
     def make(self, key):
@@ -70,12 +78,9 @@ def make(self, key):
         block_state_query = acquisition.Environment.BlockState & exp_key & chunk_restriction
         block_state_df = fetch_stream(block_state_query)
         if block_state_df.empty:
-            self.insert1(key)
+            # self.insert1(key)
             return
 
-        block_state_df.index = block_state_df.index.round(
-            "us"
-        )  # timestamp precision in DJ is only at microseconds
         block_state_df = block_state_df.loc[
             (block_state_df.index > chunk_start) & (block_state_df.index <= chunk_end)
         ]
@@ -103,7 +108,10 @@ def make(self, key):
                 )
 
         Block.insert(block_entries, skip_duplicates=True)
-        self.insert1(key)
+        # self.insert1({**key, "execution_time": datetime.now(UTC)})
+        self.IdentifiedBlock.insert(
+            {**key, "block_start": entry["block_start"]} for entry in block_entries
+        )
 
 
 # ---- Block Analysis and Visualization ----
@@ -316,6 +324,15 @@ def make(self, key):
             if _df.type.iloc[-1] != "Exit":
                 subject_names.append(subject_name)
 
+        # Check for ExperimentTimeline to validate subjects in this block
+        timeline_query = (acquisition.ExperimentTimeline
+                          & acquisition.ExperimentTimeline.Subject
+                          & key
+                          & f"start <= '{block_start}' AND end >= '{block_end}'")
+        timeline_subjects = (acquisition.ExperimentTimeline.Subject & timeline_query).fetch("subject")
+        if len(timeline_subjects):
+            subject_names = [s for s in subject_names if s in timeline_subjects]
+
         if use_blob_position and len(subject_names) > 1:
             raise ValueError(
                 f"Without SLEAPTracking, BlobPosition can only handle a single-subject block. "