diff --git a/homeassistant/components/timer/__init__.py b/homeassistant/components/timer/__init__.py
index e4aa6be1ff1..35258555537 100644
--- a/homeassistant/components/timer/__init__.py
+++ b/homeassistant/components/timer/__init__.py
@@ -55,8 +55,7 @@ STORAGE_KEY = DOMAIN
 STORAGE_VERSION = 1
 
 CREATE_FIELDS = {
-    vol.Required(CONF_NAME): vol.All(str, vol.Length(min=1)),
-    vol.Optional(CONF_NAME): cv.string,
+    vol.Required(CONF_NAME): cv.string,
     vol.Optional(CONF_ICON): cv.icon,
     vol.Optional(CONF_DURATION, default=DEFAULT_DURATION): cv.time_period,
 }
@@ -199,6 +198,9 @@ class Timer(RestoreEntity):
         self._end: datetime | None = None
         self._listener: Callable[[], None] | None = None
 
+        self._attr_should_poll = False
+        self._attr_force_update = True
+
     @classmethod
     def from_yaml(cls, config: dict) -> Timer:
         """Return entity instance initialized from yaml storage."""
@@ -207,16 +209,6 @@ class Timer(RestoreEntity):
         timer.editable = False
         return timer
 
-    @property
-    def should_poll(self):
-        """If entity should be polled."""
-        return False
-
-    @property
-    def force_update(self) -> bool:
-        """Return True to fix restart issues."""
-        return True
-
     @property
     def name(self):
         """Return name of the timer."""
@@ -266,9 +258,6 @@ class Timer(RestoreEntity):
         if self._listener:
             self._listener()
             self._listener = None
-        newduration = None
-        if duration:
-            newduration = duration
 
         event = EVENT_TIMER_STARTED
         if self._state in (STATUS_ACTIVE, STATUS_PAUSED):
@@ -277,17 +266,13 @@ class Timer(RestoreEntity):
         self._state = STATUS_ACTIVE
         start = dt_util.utcnow().replace(microsecond=0)
 
-        if self._remaining and newduration is None:
-            self._end = start + self._remaining
-
-        elif newduration:
-            self._duration = newduration
-            self._remaining = newduration
-            self._end = start + self._duration
-
-        else:
+        # Set remaining to new value if needed
+        if duration:
+            self._remaining = self._duration = duration
+        elif not self._remaining:
             self._remaining = self._duration
-            self._end = start + self._duration
+
+        self._end = start + self._remaining
 
         self.hass.bus.async_fire(event, {"entity_id": self.entity_id})
 
diff --git a/tests/components/timer/test_init.py b/tests/components/timer/test_init.py
index 92958a7bce6..5c276bc0cfc 100644
--- a/tests/components/timer/test_init.py
+++ b/tests/components/timer/test_init.py
@@ -8,6 +8,7 @@ import pytest
 
 from homeassistant.components.timer import (
     ATTR_DURATION,
+    ATTR_REMAINING,
     CONF_DURATION,
     CONF_ICON,
     CONF_NAME,
@@ -190,6 +191,46 @@ async def test_methods_and_events(hass):
             assert len(results) == expectedEvents
 
 
+async def test_start_service(hass):
+    """Test the start/stop service."""
+    await async_setup_component(hass, DOMAIN, {DOMAIN: {"test1": {CONF_DURATION: 10}}})
+
+    state = hass.states.get("timer.test1")
+    assert state
+    assert state.state == STATUS_IDLE
+    assert state.attributes[ATTR_DURATION] == "0:00:10"
+
+    await hass.services.async_call(
+        DOMAIN, SERVICE_START, {CONF_ENTITY_ID: "timer.test1"}
+    )
+    await hass.async_block_till_done()
+    state = hass.states.get("timer.test1")
+    assert state
+    assert state.state == STATUS_ACTIVE
+    assert state.attributes[ATTR_DURATION] == "0:00:10"
+    assert state.attributes[ATTR_REMAINING] == "0:00:10"
+
+    await hass.services.async_call(
+        DOMAIN, SERVICE_CANCEL, {CONF_ENTITY_ID: "timer.test1"}
+    )
+    await hass.async_block_till_done()
+    state = hass.states.get("timer.test1")
+    assert state
+    assert state.state == STATUS_IDLE
+    assert state.attributes[ATTR_DURATION] == "0:00:10"
+    assert ATTR_REMAINING not in state.attributes
+
+    await hass.services.async_call(
+        DOMAIN, SERVICE_START, {CONF_ENTITY_ID: "timer.test1", CONF_DURATION: 15}
+    )
+    await hass.async_block_till_done()
+    state = hass.states.get("timer.test1")
+    assert state
+    assert state.state == STATUS_ACTIVE
+    assert state.attributes[ATTR_DURATION] == "0:00:15"
+    assert state.attributes[ATTR_REMAINING] == "0:00:15"
+
+
 async def test_wait_till_timer_expires(hass):
     """Test for a timer to end."""
     hass.state = CoreState.starting