diff --git a/tests/test_param.py b/tests/test_param.py
index 36377cff9..c9f91a294 100644
--- a/tests/test_param.py
+++ b/tests/test_param.py
@@ -30,3 +30,15 @@ def test_multiple_positional_args(a, b):
 ])
 def test_non_literal_with_id(data):
     pass
+
+from datetime import datetime, timedelta
+
+testdata = [
+    (datetime(2001, 12, 12), datetime(2001, 12, 11), timedelta(1)),
+    (datetime(2001, 12, 11), datetime(2001, 12, 12), timedelta(-1)),
+]
+
+@pytest.mark.parametrize("a,b,expected", testdata, ids=["forward", "backward"])
+def test_timedistance_v1(a, b, expected):
+    diff = a - b
+    assert diff == expected
\ No newline at end of file