diff --git a/homeassistant/util/dt.py b/homeassistant/util/dt.py
index d16e02913b5..3b202dad1cb 100644
--- a/homeassistant/util/dt.py
+++ b/homeassistant/util/dt.py
@@ -213,9 +213,13 @@ def parse_time_expression(parameter: Any, min_value: int, max_value: int) -> Lis
     """Parse the time expression part and return a list of times to match."""
     if parameter is None or parameter == MATCH_ALL:
         res = list(range(min_value, max_value + 1))
-    elif isinstance(parameter, str) and parameter.startswith("/"):
-        parameter = int(parameter[1:])
-        res = [x for x in range(min_value, max_value + 1) if x % parameter == 0]
+    elif isinstance(parameter, str):
+        if parameter.startswith("/"):
+            parameter = int(parameter[1:])
+            res = [x for x in range(min_value, max_value + 1) if x % parameter == 0]
+        else:
+            res = [int(parameter)]
+
     elif not hasattr(parameter, "__iter__"):
         res = [int(parameter)]
     else:
diff --git a/tests/util/test_dt.py b/tests/util/test_dt.py
index 03d4ee53cbe..7c4ca77fd79 100644
--- a/tests/util/test_dt.py
+++ b/tests/util/test_dt.py
@@ -187,6 +187,7 @@ def test_parse_time_expression():
     assert [x for x in range(24)] == dt_util.parse_time_expression("*", 0, 23)
 
     assert [42] == dt_util.parse_time_expression(42, 0, 59)
+    assert [42] == dt_util.parse_time_expression("42", 0, 59)
 
     with pytest.raises(ValueError):
         dt_util.parse_time_expression(61, 0, 60)