diff --git a/homeassistant/helpers/condition.py b/homeassistant/helpers/condition.py
index a467d952683..d3020b8d6d8 100644
--- a/homeassistant/helpers/condition.py
+++ b/homeassistant/helpers/condition.py
@@ -16,7 +16,9 @@ from homeassistant.components import zone as zone_cmp
 from homeassistant.components.device_automation import (
     async_get_device_automation_platform,
 )
+from homeassistant.components.sensor import DEVICE_CLASS_TIMESTAMP
 from homeassistant.const import (
+    ATTR_DEVICE_CLASS,
     ATTR_GPS_ACCURACY,
     ATTR_LATITUDE,
     ATTR_LONGITUDE,
@@ -736,11 +738,24 @@ def time(
         after_entity = hass.states.get(after)
         if not after_entity:
             raise ConditionErrorMessage("time", f"unknown 'after' entity {after}")
-        after = dt_util.dt.time(
-            after_entity.attributes.get("hour", 23),
-            after_entity.attributes.get("minute", 59),
-            after_entity.attributes.get("second", 59),
-        )
+        if after_entity.domain == "input_datetime":
+            after = dt_util.dt.time(
+                after_entity.attributes.get("hour", 23),
+                after_entity.attributes.get("minute", 59),
+                after_entity.attributes.get("second", 59),
+            )
+        elif after_entity.attributes.get(
+            ATTR_DEVICE_CLASS
+        ) == DEVICE_CLASS_TIMESTAMP and after_entity.state not in (
+            STATE_UNAVAILABLE,
+            STATE_UNKNOWN,
+        ):
+            after_datetime = dt_util.parse_datetime(after_entity.state)
+            if after_datetime is None:
+                return False
+            after = dt_util.as_local(after_datetime).time()
+        else:
+            return False
 
     if before is None:
         before = dt_util.dt.time(23, 59, 59, 999999)
@@ -748,11 +763,24 @@ def time(
         before_entity = hass.states.get(before)
         if not before_entity:
             raise ConditionErrorMessage("time", f"unknown 'before' entity {before}")
-        before = dt_util.dt.time(
-            before_entity.attributes.get("hour", 23),
-            before_entity.attributes.get("minute", 59),
-            before_entity.attributes.get("second", 59),
-        )
+        if before_entity.domain == "input_datetime":
+            before = dt_util.dt.time(
+                before_entity.attributes.get("hour", 23),
+                before_entity.attributes.get("minute", 59),
+                before_entity.attributes.get("second", 59),
+            )
+        elif before_entity.attributes.get(
+            ATTR_DEVICE_CLASS
+        ) == DEVICE_CLASS_TIMESTAMP and before_entity.state not in (
+            STATE_UNAVAILABLE,
+            STATE_UNKNOWN,
+        ):
+            before_timedatime = dt_util.parse_datetime(before_entity.state)
+            if before_timedatime is None:
+                return False
+            before = dt_util.as_local(before_timedatime).time()
+        else:
+            return False
 
     if after < before:
         condition_trace_update_result(after=after, now_time=now_time, before=before)
diff --git a/homeassistant/helpers/config_validation.py b/homeassistant/helpers/config_validation.py
index 88f38f0a688..324173ed2e8 100644
--- a/homeassistant/helpers/config_validation.py
+++ b/homeassistant/helpers/config_validation.py
@@ -1014,8 +1014,12 @@ TIME_CONDITION_SCHEMA = vol.All(
         {
             **CONDITION_BASE_SCHEMA,
             vol.Required(CONF_CONDITION): "time",
-            "before": vol.Any(time, vol.All(str, entity_domain("input_datetime"))),
-            "after": vol.Any(time, vol.All(str, entity_domain("input_datetime"))),
+            "before": vol.Any(
+                time, vol.All(str, entity_domain(["input_datetime", "sensor"]))
+            ),
+            "after": vol.Any(
+                time, vol.All(str, entity_domain(["input_datetime", "sensor"]))
+            ),
             "weekday": weekdays,
         }
     ),
diff --git a/tests/helpers/test_condition.py b/tests/helpers/test_condition.py
index 973196d29f8..d75dd53bbf2 100644
--- a/tests/helpers/test_condition.py
+++ b/tests/helpers/test_condition.py
@@ -6,7 +6,8 @@ import pytest
 
 from homeassistant.components import sun
 import homeassistant.components.automation as automation
-from homeassistant.const import SUN_EVENT_SUNRISE, SUN_EVENT_SUNSET
+from homeassistant.components.sensor import DEVICE_CLASS_TIMESTAMP
+from homeassistant.const import ATTR_DEVICE_CLASS, SUN_EVENT_SUNRISE, SUN_EVENT_SUNSET
 from homeassistant.exceptions import ConditionError, HomeAssistantError
 from homeassistant.helpers import condition, trace
 from homeassistant.helpers.template import Template
@@ -826,6 +827,90 @@ async def test_time_using_input_datetime(hass):
         condition.time(hass, before="input_datetime.not_existing")
 
 
+async def test_time_using_sensor(hass):
+    """Test time conditions using sensor entities."""
+    hass.states.async_set(
+        "sensor.am",
+        "2021-06-03 13:00:00.000000+00:00",  # 6 am local time
+        {ATTR_DEVICE_CLASS: DEVICE_CLASS_TIMESTAMP},
+    )
+    hass.states.async_set(
+        "sensor.pm",
+        "2020-06-01 01:00:00.000000+00:00",  # 6 pm local time
+        {ATTR_DEVICE_CLASS: DEVICE_CLASS_TIMESTAMP},
+    )
+    hass.states.async_set(
+        "sensor.no_device_class",
+        "2020-06-01 01:00:00.000000+00:00",
+    )
+    hass.states.async_set(
+        "sensor.invalid_timestamp",
+        "This is not a timestamp",
+        {ATTR_DEVICE_CLASS: DEVICE_CLASS_TIMESTAMP},
+    )
+
+    with patch(
+        "homeassistant.helpers.condition.dt_util.now",
+        return_value=dt_util.now().replace(hour=3),
+    ):
+        assert not condition.time(hass, after="sensor.am", before="sensor.pm")
+        assert condition.time(hass, after="sensor.pm", before="sensor.am")
+
+    with patch(
+        "homeassistant.helpers.condition.dt_util.now",
+        return_value=dt_util.now().replace(hour=9),
+    ):
+        assert condition.time(hass, after="sensor.am", before="sensor.pm")
+        assert not condition.time(hass, after="sensor.pm", before="sensor.am")
+
+    with patch(
+        "homeassistant.helpers.condition.dt_util.now",
+        return_value=dt_util.now().replace(hour=15),
+    ):
+        assert condition.time(hass, after="sensor.am", before="sensor.pm")
+        assert not condition.time(hass, after="sensor.pm", before="sensor.am")
+
+    with patch(
+        "homeassistant.helpers.condition.dt_util.now",
+        return_value=dt_util.now().replace(hour=21),
+    ):
+        assert not condition.time(hass, after="sensor.am", before="sensor.pm")
+        assert condition.time(hass, after="sensor.pm", before="sensor.am")
+
+    # Trigger on PM time
+    with patch(
+        "homeassistant.helpers.condition.dt_util.now",
+        return_value=dt_util.now().replace(hour=18, minute=0, second=0),
+    ):
+        assert condition.time(hass, after="sensor.pm", before="sensor.am")
+        assert not condition.time(hass, after="sensor.am", before="sensor.pm")
+        assert condition.time(hass, after="sensor.pm")
+        assert not condition.time(hass, before="sensor.pm")
+
+        # Even though valid, the device class is missing
+        assert not condition.time(hass, after="sensor.no_device_class")
+        assert not condition.time(hass, before="sensor.no_device_class")
+
+    # Trigger on AM time
+    with patch(
+        "homeassistant.helpers.condition.dt_util.now",
+        return_value=dt_util.now().replace(hour=6, minute=0, second=0),
+    ):
+        assert not condition.time(hass, after="sensor.pm", before="sensor.am")
+        assert condition.time(hass, after="sensor.am", before="sensor.pm")
+        assert condition.time(hass, after="sensor.am")
+        assert not condition.time(hass, before="sensor.am")
+
+    assert not condition.time(hass, after="sensor.invalid_timestamp")
+    assert not condition.time(hass, before="sensor.invalid_timestamp")
+
+    with pytest.raises(ConditionError):
+        condition.time(hass, after="sensor.not_existing")
+
+    with pytest.raises(ConditionError):
+        condition.time(hass, before="sensor.not_existing")
+
+
 async def test_state_raises(hass):
     """Test that state raises ConditionError on errors."""
     # No entity