diff --git a/pkg-py/src/querychat/_datasource.py b/pkg-py/src/querychat/_datasource.py
index 56377502..466e0548 100644
--- a/pkg-py/src/querychat/_datasource.py
+++ b/pkg-py/src/querychat/_datasource.py
@@ -210,7 +210,7 @@ def get_schema(self, *, categorical_threshold: int) -> str:
             elif dtype == nw.Boolean:
                 sql_type = "BOOLEAN"
             elif dtype == nw.Datetime:
-                sql_type = "TIME"
+                sql_type = "TIMESTAMP"
             elif dtype == nw.Date:
                 sql_type = "DATE"
             else:
@@ -224,7 +224,7 @@ def get_schema(self, *, categorical_threshold: int) -> str:
                     categories = unique_values.to_list()
                     categories_str = ", ".join([f"'{c}'" for c in categories])
                     column_info.append(f"  Categorical values: {categories_str}")
-            elif sql_type in ["INTEGER", "FLOAT", "DATE", "TIME"]:
+            elif sql_type in ["INTEGER", "FLOAT", "DATE", "TIMESTAMP"]:
                 rng = self._df[column].min(), self._df[column].max()
                 if rng[0] is None and rng[1] is None:
                     column_info.append("  Range: NULL to NULL")
diff --git a/pkg-py/tests/test_datasource.py b/pkg-py/tests/test_datasource.py
index 8ba00fee..d3b04e06 100644
--- a/pkg-py/tests/test_datasource.py
+++ b/pkg-py/tests/test_datasource.py
@@ -498,3 +498,27 @@ def test_check_query_escape_hatch_accepts_various_values(monkeypatch):
     for value in ["true", "TRUE", "1", "yes", "YES"]:
         monkeypatch.setenv("QUERYCHAT_ENABLE_UPDATE_QUERIES", value)
         check_query("INSERT INTO table VALUES (1)")  # Should not raise
+
+
+def test_dataframe_source_datetime_type_mapping():
+    """Test that datetime columns are mapped to TIMESTAMP, not TIME."""
+    # Create DataFrame with datetime column
+    test_df = pd.DataFrame(
+        {
+            "id": [1, 2, 3],
+            "name": ["a", "b", "c"],
+            "created_at": pd.to_datetime(["2023-01-01 10:00:00", "2023-06-15 14:30:00", "2023-12-31 23:59:59"]),
+        }
+    )
+
+    source = DataFrameSource(test_df, "test_table")
+    schema = source.get_schema(categorical_threshold=5)
+
+    # Datetime columns should be TIMESTAMP, not TIME
+    assert "- created_at (TIMESTAMP)" in schema
+    assert "- created_at (TIME)" not in schema
+
+    # Should also show range for datetime columns
+    assert "Range:" in schema
+
+    source.cleanup()