diff --git a/swh/provenance/graph.py b/swh/provenance/graph.py
--- a/swh/provenance/graph.py
+++ b/swh/provenance/graph.py
@@ -239,19 +239,16 @@
                 # we can infer the maxdate for current directory
                 assert current.maxdate is None
                 # if all content is already known, update current directory info.
-                current.maxdate = min(
-                    max(
-                        [UTCMIN]
-                        + [
-                            child.maxdate
-                            for child in current.children
-                            if child.maxdate is not None  # for mypy
-                        ]
-                        + [
-                            fdates.get(file.id, revision.date)
-                            for file in current.entry.files
-                        ]
-                    ),
-                    revision.date,
+                current.maxdate = max(
+                    [UTCMIN]
+                    + [
+                        child.maxdate
+                        for child in current.children
+                        if child.maxdate is not None  # for mypy
+                    ]
+                    + [
+                        fdates.get(file.id, revision.date)
+                        for file in current.entry.files
+                    ]
                 )
     return root
diff --git a/swh/provenance/revision.py b/swh/provenance/revision.py
--- a/swh/provenance/revision.py
+++ b/swh/provenance/revision.py
@@ -110,7 +110,7 @@
     while stack:
         current = stack.pop()
         if current.dbdate is not None:
-            assert current.dbdate <= revision.date
+            assert current.dbdate < revision.date
             if trackall:
                 # Current directory is an outer isochrone frontier for a previously
                 # processed revision. It should be reused as is.
@@ -146,7 +146,7 @@
                 # revisions to get the proper value.
                 if current.invalid:
                     provenance.directory_set_date_in_isochrone_frontier(
-                        current.entry, current.maxdate
+                        current.entry, revision.date
                     )
                 # No point moving the frontier here. Either there are no files or they
                 # are being seen for the first time here. Add all blobs to current
diff --git a/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml b/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml
--- a/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml
+++ b/swh/provenance/tests/data/graphs_out-of-order_lower_1.yaml
@@ -124,25 +124,25 @@
     entry:
       id: "b3cf11b22c9f93c3c494cf90ab072f394155072d"
       name: ""
-    maxdate: 1000000005.0
+    maxdate: 1000000010.0
     path: ""
     children:
       - entry:
           id: "baca735bf8b8720131b4bfdb47c51631a9260348"
           name: "A"
-        maxdate: 1000000005.0
+        maxdate: 1000000010.0
         path: "A"
         children:
           - entry:
               id: "4b28979d88ed209a09c272bcc80f69d9b18339c2"
               name: "B"
-            maxdate: 1000000005.0
+            maxdate: 1000000010.0
             path: "A/B"
             children:
             - entry:
                 id: "c9cabe7f49012e3fdef6ac6b929efb5654f583cf"
                 name: "C"
-              maxdate: 1000000005.0
+              maxdate: 1000000010.0
               invalid: True
               path: "A/B/C"
 # Isochrone graph for R06