diff --git a/superset/viz.py b/superset/viz.py
index 8dabed663b..1e67596bf2 100644
--- a/superset/viz.py
+++ b/superset/viz.py
@@ -1405,8 +1405,8 @@ class NVD3TimeSeriesViz(NVD3Viz):
             if not query_object["from_dttm"] or not query_object["to_dttm"]:
                 raise QueryObjectValidationError(
                     _(
-                        "`Since` and `Until` time bounds should be specified "
-                        "when using the `Time Shift` feature."
+                        "An enclosed time range (both start and end) must be specified "
+                        "when using a Time Comparison."
                     )
                 )
             query_object["from_dttm"] -= delta
diff --git a/superset/viz_sip38.py b/superset/viz_sip38.py
index 5c9b6fb0bf..d9f6f72dfc 100644
--- a/superset/viz_sip38.py
+++ b/superset/viz_sip38.py
@@ -1275,8 +1275,8 @@ class NVD3TimeSeriesViz(NVD3Viz):
             if not query_object["from_dttm"] or not query_object["to_dttm"]:
                 raise QueryObjectValidationError(
                     _(
-                        "`Since` and `Until` time bounds should be specified "
-                        "when using the `Time Shift` feature."
+                        "An enclosed time range (both start and end) must be specified "
+                        "when using a Time Comparison."
                     )
                 )
             query_object["from_dttm"] -= delta