diff --git a/homeassistant/components/jewish_calendar/sensor.py b/homeassistant/components/jewish_calendar/sensor.py
index 0dfc61970ef..17a61c932a3 100644
--- a/homeassistant/components/jewish_calendar/sensor.py
+++ b/homeassistant/components/jewish_calendar/sensor.py
@@ -1,4 +1,5 @@
 """Platform to retrieve Jewish calendar information for Home Assistant."""
+from datetime import datetime
 import logging
 
 import hdate
@@ -51,6 +52,8 @@ class JewishCalendarSensor(SensorEntity):
     @property
     def state(self):
         """Return the state of the sensor."""
+        if isinstance(self._state, datetime):
+            return self._state.isoformat()
         return self._state
 
     async def async_update(self):
@@ -133,7 +136,9 @@ class JewishCalendarTimeSensor(JewishCalendarSensor):
     @property
     def state(self):
         """Return the state of the sensor."""
-        return dt_util.as_utc(self._state) if self._state is not None else None
+        if self._state is None:
+            return None
+        return dt_util.as_utc(self._state).isoformat()
 
     @property
     def extra_state_attributes(self):
diff --git a/tests/components/jewish_calendar/test_sensor.py b/tests/components/jewish_calendar/test_sensor.py
index 970e31c7985..e9471d5d144 100644
--- a/tests/components/jewish_calendar/test_sensor.py
+++ b/tests/components/jewish_calendar/test_sensor.py
@@ -188,13 +188,13 @@ async def test_jewish_calendar_sensor(
         await hass.async_block_till_done()
 
     result = (
-        dt_util.as_utc(result.replace(tzinfo=time_zone))
+        dt_util.as_utc(result.replace(tzinfo=time_zone)).isoformat()
         if isinstance(result, dt)
         else result
     )
 
     sensor_object = hass.states.get(f"sensor.test_{sensor}")
-    assert sensor_object.state == str(result)
+    assert sensor_object.state == result
 
     if sensor == "holiday":
         assert sensor_object.attributes.get("id") == "rosh_hashana_i"
@@ -544,7 +544,7 @@ async def test_shabbat_times_sensor(
         sensor_type = sensor_type.replace(f"{language}_", "")
 
         result_value = (
-            dt_util.as_utc(result_value)
+            dt_util.as_utc(result_value).isoformat()
             if isinstance(result_value, dt)
             else result_value
         )