diff --git a/swh/scheduler/journal_client.py b/swh/scheduler/journal_client.py
--- a/swh/scheduler/journal_client.py
+++ b/swh/scheduler/journal_client.py
@@ -14,18 +14,23 @@
 msg_type = "origin_visit_status"
 
 
-def max_date(d1: Optional[datetime], d2: Optional[datetime]) -> datetime:
-    """Return the max date of the visit stats
+def max_date(*dates: Optional[datetime]) -> datetime:
+    """Return the max date of given (possibly None) dates
 
+    At least one date must be not None.
     """
-    if d1 is None and d2 is None:
+    datesok: Tuple[datetime, ...] = tuple(d for d in dates if d is not None)
+    if not datesok:
         raise ValueError("At least one date should be a valid datetime")
-    if d1 is None:
-        assert d2 is not None  # make mypy happy
-        return d2
-    if d2 is None:
-        return d1
-    return max(d1, d2)
+
+    maxdate = datesok[0]
+    if len(datesok) == 1:
+        return maxdate
+
+    for d in datesok[1:]:
+        maxdate = max(d, maxdate)
+
+    return maxdate
 
 
 def process_journal_objects(
diff --git a/swh/scheduler/tests/test_journal_client.py b/swh/scheduler/tests/test_journal_client.py
--- a/swh/scheduler/tests/test_journal_client.py
+++ b/swh/scheduler/tests/test_journal_client.py
@@ -36,19 +36,28 @@
 
 
 @pytest.mark.parametrize(
-    "d1,d2,expected_max_date",
+    "dates,expected_max_date",
     [
-        (None, DATE2, DATE2),
-        (DATE1, None, DATE1),
-        (DATE1, DATE2, DATE2),
-        (DATE2, DATE1, DATE2),
+        ((DATE1,), DATE1),
+        ((None, DATE2), DATE2),
+        ((DATE1, None), DATE1),
+        ((DATE1, DATE2), DATE2),
+        ((DATE2, DATE1), DATE2),
+        ((DATE1, DATE2, DATE3), DATE3),
+        ((None, DATE2, DATE3), DATE3),
+        ((None, None, DATE3), DATE3),
+        ((DATE1, None, DATE3), DATE3),
     ],
 )
-def test_max_date(d1, d2, expected_max_date):
-    assert max_date(d1, d2) == expected_max_date
+def test_max_date(dates, expected_max_date):
+    assert max_date(*dates) == expected_max_date
 
 
 def test_max_date_raise():
+    with pytest.raises(ValueError, match="valid datetime"):
+        max_date()
+    with pytest.raises(ValueError, match="valid datetime"):
+        max_date(None)
     with pytest.raises(ValueError, match="valid datetime"):
         max_date(None, None)