diff --git a/app/seed.py b/app/seed.py
index 2794518..c11cae0 100644
--- a/app/seed.py
+++ b/app/seed.py
@@ -46,8 +46,12 @@ def _load_dir(subdir: Path) -> list[dict[str, Any]]:
     for path in sorted(subdir.rglob("*.json")):  # recurse into brand subfolders
         record = json.loads(path.read_text(encoding="utf-8"))
         # SQLModel table models skip validation, so coerce ISO date strings here.
-        if isinstance(record.get("release_date"), str):
-            record["release_date"] = date.fromisoformat(record["release_date"])
+        # Keyed on the *_date suffix rather than one field name: a category whose
+        # date column is not called release_date (website.launch_date) would
+        # otherwise reach SQLite as a str and fail the insert.
+        for key, value in list(record.items()):
+            if key.endswith("_date") and isinstance(value, str):
+                record[key] = date.fromisoformat(value)
         items.append(record)
     return items
 
diff --git a/tests/unit/test_seed_date_coercion.py b/tests/unit/test_seed_date_coercion.py
new file mode 100644
index 0000000..eb950f0
--- /dev/null
+++ b/tests/unit/test_seed_date_coercion.py
@@ -0,0 +1,55 @@
+"""The seed loader must turn ISO date strings into date objects.
+
+Regression test for a category whose date column is not named ``release_date``:
+websites use ``launch_date``, and while the field-name-specific coercion was in
+place such a record reached SQLite as a str and the insert failed with
+"SQLite Date type only accepts Python date objects as input".
+
+The endpoint tests insert fixtures through the model with real date objects, so
+they never covered the JSON -> DB path this exercises.
+"""
+
+from __future__ import annotations
+
+import json
+from datetime import date
+from pathlib import Path
+
+from app.seed import _load_dir
+
+
+def test_load_dir_coerces_any_date_suffixed_field(tmp_path: Path) -> None:
+    (tmp_path / "a.json").write_text(
+        json.dumps(
+            {
+                "slug": "example-site",
+                "name": "Example",
+                "launch_date": "2001-01-15",
+                "release_date": "1998-01-02",
+                "verified": False,
+                "source_urls": ["https://example.com"],
+            }
+        ),
+        encoding="utf-8",
+    )
+
+    records = _load_dir(tmp_path)
+
+    assert len(records) == 1
+    assert records[0]["launch_date"] == date(2001, 1, 15)
+    assert records[0]["release_date"] == date(1998, 1, 2)
+
+
+def test_load_dir_leaves_non_date_fields_alone(tmp_path: Path) -> None:
+    (tmp_path / "a.json").write_text(
+        json.dumps({"slug": "x", "name": "X", "homepage_url": "https://x.example"}),
+        encoding="utf-8",
+    )
+
+    records = _load_dir(tmp_path)
+
+    assert records[0]["homepage_url"] == "https://x.example"
+
+
+def test_load_dir_missing_directory_is_empty(tmp_path: Path) -> None:
+    assert _load_dir(tmp_path / "nope") == []