diff --git a/humanfriendly/__init__.py b/humanfriendly/__init__.py
index 4c0a333..19e053f 100644
--- a/humanfriendly/__init__.py
+++ b/humanfriendly/__init__.py
@@ -582,10 +582,12 @@ def parse_date(datestring):
         if len(tokens) >= 2:
             date_parts = list(map(int, tokens[0].split('-'))) + [1, 1]
             time_parts = list(map(int, tokens[1].split(':'))) + [0, 0, 0]
-            return tuple(date_parts[0:3] + time_parts[0:3])
+            result = tuple(date_parts[0:3] + time_parts[0:3])
         else:
             year, month, day = (list(map(int, datestring.split('-'))) + [1, 1])[0:3]
-            return (year, month, day, 0, 0, 0)
+            result = (year, month, day, 0, 0, 0)
+        datetime.datetime(*result)
+        return result
     except Exception:
         msg = "Invalid date! (expected 'YYYY-MM-DD' or 'YYYY-MM-DD HH:MM:SS' but got: %r)"
         raise InvalidDate(format(msg, datestring))
diff --git a/humanfriendly/tests.py b/humanfriendly/tests.py
index 72dad99..035650a 100644
--- a/humanfriendly/tests.py
+++ b/humanfriendly/tests.py
@@ -490,6 +490,22 @@ def test_parse_date(self):
         with self.assertRaises(InvalidDate):
             parse_date('2013-06-XY')
 
+    def test_parse_date_rejects_invalid_calendar_values(self):
+        """Raise InvalidDate for dates that cannot be used as datetimes."""
+        for value in ['2023-02-29', '2024-02-30', '2024-04-31', '2024-00-10',
+                      '2024-13-10', '2024-01-00', '0000-01-01', '10000-01-01',
+                      '2024-01-01 24:00:00', '2024-01-01 12:60:00',
+                      '2024-01-01 12:00:60']:
+            with self.assertRaises(InvalidDate):
+                parse_date(value)
+
+    def test_parse_date_preserves_valid_and_partial_dates(self):
+        """Keep leap days and the existing defaults for omitted components."""
+        assert parse_date('2024-02-29') == (2024, 2, 29, 0, 0, 0)
+        assert parse_date('2024') == (2024, 1, 1, 0, 0, 0)
+        assert parse_date('2024-02') == (2024, 2, 1, 0, 0, 0)
+        assert parse_date('2024-02-29 23:59:59') == (2024, 2, 29, 23, 59, 59)
+
     def test_format_size(self):
         """Test :func:`humanfriendly.format_size()`."""
         self.assertEqual('0 bytes', format_size(0))