diff --git a/superset/utils/date_parser.py b/superset/utils/date_parser.py
index 9a7c135f5c159..bffe50c6242c3 100644
--- a/superset/utils/date_parser.py
+++ b/superset/utils/date_parser.py
@@ -263,9 +263,10 @@ def get_since_until(  # pylint: disable=too-many-arguments,too-many-locals,too-m
         )
 
     if time_shift:
-        time_delta = parse_past_timedelta(time_shift)
-        _since = _since if _since is None else (_since - time_delta)
-        _until = _until if _until is None else (_until - time_delta)
+        time_delta_since = parse_past_timedelta(time_shift, _since)
+        time_delta_until = parse_past_timedelta(time_shift, _until)
+        _since = _since if _since is None else (_since - time_delta_since)
+        _until = _until if _until is None else (_until - time_delta_until)
 
     if instant_time_comparison_range:
         # This is only set using the new time comparison controls
diff --git a/tests/unit_tests/utils/date_parser_tests.py b/tests/unit_tests/utils/date_parser_tests.py
index b031e54a664c8..201adc4934e93 100644
--- a/tests/unit_tests/utils/date_parser_tests.py
+++ b/tests/unit_tests/utils/date_parser_tests.py
@@ -165,28 +165,49 @@ def test_get_since_until() -> None:
         time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
         instant_time_comparison_range="y",
     )
-    expected = datetime(2000, 1, 1), datetime(2018, 1, 1)
+    expected = datetime(1999, 1, 1), datetime(2017, 1, 1)
     assert result == expected
 
     result = get_since_until(
         time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
         instant_time_comparison_range="m",
     )
-    expected = datetime(2000, 1, 1), datetime(2018, 1, 1)
+    expected = datetime(1999, 12, 1), datetime(2017, 12, 1)
     assert result == expected
 
     result = get_since_until(
         time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
         instant_time_comparison_range="w",
     )
-    expected = datetime(2000, 1, 1), datetime(2018, 1, 1)
+    expected = datetime(1999, 12, 25), datetime(2017, 12, 25)
     assert result == expected
 
     result = get_since_until(
         time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
         instant_time_comparison_range="r",
     )
-    expected = datetime(2000, 1, 1), datetime(2018, 1, 1)
+    expected = datetime(1981, 12, 31), datetime(2000, 1, 1)
+    assert result == expected
+
+    result = get_since_until(
+        time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
+        time_shift="1 year ago",
+    )
+    expected = datetime(1999, 1, 1), datetime(2017, 1, 1)
+    assert result == expected
+
+    result = get_since_until(
+        time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
+        time_shift="1 month ago",
+    )
+    expected = datetime(1999, 12, 1), datetime(2017, 12, 1)
+    assert result == expected
+
+    result = get_since_until(
+        time_range="2000-01-01T00:00:00 : 2018-01-01T00:00:00",
+        time_shift="1 week ago",
+    )
+    expected = datetime(1999, 12, 25), datetime(2017, 12, 25)
     assert result == expected
 
     with pytest.raises(ValueError):