diff --git a/homeassistant/components/time_date/sensor.py b/homeassistant/components/time_date/sensor.py
index b9012385296..8be0e2d8c66 100644
--- a/homeassistant/components/time_date/sensor.py
+++ b/homeassistant/components/time_date/sensor.py
@@ -80,7 +80,7 @@ class TimeDateSensor(Entity):
         return "mdi:clock"
 
     async def async_added_to_hass(self) -> None:
-        """Set up next update."""
+        """Set up first update."""
         self.unsub = async_track_point_in_utc_time(
             self.hass, self.point_in_time_listener, self.get_next_interval()
         )
@@ -91,20 +91,24 @@ class TimeDateSensor(Entity):
             self.unsub()
             self.unsub = None
 
-    def get_next_interval(self, now=None):
+    def get_next_interval(self):
         """Compute next time an update should occur."""
-        if now is None:
-            now = dt_util.utcnow()
+        now = dt_util.utcnow()
+
         if self.type == "date":
             now = dt_util.start_of_local_day(dt_util.as_local(now))
             return now + timedelta(seconds=86400)
+
         if self.type == "beat":
             interval = 86.4
         else:
             interval = 60
         timestamp = int(dt_util.as_timestamp(now))
         delta = interval - (timestamp % interval)
-        return now + timedelta(seconds=delta)
+        next_interval = now + timedelta(seconds=delta)
+        _LOGGER.debug("%s + %s -> %s (%s)", now, delta, next_interval, self.type)
+
+        return next_interval
 
     def _update_internal_state(self, time_date):
         time = dt_util.as_local(time_date).strftime(TIME_STR_FORMAT)
diff --git a/tests/components/time_date/test_sensor.py b/tests/components/time_date/test_sensor.py
index a20afb61fe3..b5116478678 100644
--- a/tests/components/time_date/test_sensor.py
+++ b/tests/components/time_date/test_sensor.py
@@ -21,17 +21,20 @@ async def test_intervals(hass):
     """Test timing intervals of sensors."""
     device = time_date.TimeDateSensor(hass, "time")
     now = dt_util.utc_from_timestamp(45)
-    next_time = device.get_next_interval(now)
+    with patch("homeassistant.util.dt.utcnow", return_value=now):
+        next_time = device.get_next_interval()
     assert next_time == dt_util.utc_from_timestamp(60)
 
     device = time_date.TimeDateSensor(hass, "beat")
     now = dt_util.utc_from_timestamp(29)
-    next_time = device.get_next_interval(now)
+    with patch("homeassistant.util.dt.utcnow", return_value=now):
+        next_time = device.get_next_interval()
     assert next_time == dt_util.utc_from_timestamp(86.4)
 
     device = time_date.TimeDateSensor(hass, "date_time")
     now = dt_util.utc_from_timestamp(1495068899)
-    next_time = device.get_next_interval(now)
+    with patch("homeassistant.util.dt.utcnow", return_value=now):
+        next_time = device.get_next_interval()
     assert next_time == dt_util.utc_from_timestamp(1495068900)
 
     now = dt_util.utcnow()
@@ -117,7 +120,8 @@ async def test_timezone_intervals(hass):
 
     device = time_date.TimeDateSensor(hass, "date")
     now = dt_util.utc_from_timestamp(50000)
-    next_time = device.get_next_interval(now)
+    with patch("homeassistant.util.dt.utcnow", return_value=now):
+        next_time = device.get_next_interval()
     # start of local day in EST was 18000.0
     # so the second day was 18000 + 86400
     assert next_time.timestamp() == 104400
@@ -127,7 +131,8 @@ async def test_timezone_intervals(hass):
     dt_util.set_default_time_zone(new_tz)
     now = dt_util.parse_datetime("2017-11-13 19:47:19-07:00")
     device = time_date.TimeDateSensor(hass, "date")
-    next_time = device.get_next_interval(now)
+    with patch("homeassistant.util.dt.utcnow", return_value=now):
+        next_time = device.get_next_interval()
     assert next_time.timestamp() == dt_util.as_timestamp("2017-11-14 00:00:00-07:00")