diff --git a/custom_components/nestquest/__init__.py b/custom_components/nestquest/__init__.py
index 52a5eeb..6615679 100644
--- a/custom_components/nestquest/__init__.py
+++ b/custom_components/nestquest/__init__.py
@@ -23,6 +23,7 @@ from .const import (
     DEFAULT_HORIZON_DAYS,
     DOMAIN,
     LOGGER,
+    SERVICE_REGENERATE,
 )
 from .db import NestQuestDatabase
 from .materialize import materialize as _materialize_run
@@ -272,6 +273,29 @@ def _day_rollover_hour_minute(options: dict[str, Any]) -> tuple[int, int]:
     return int(hour), int(minute)
 
 
+async def _run_horizon_materialization(
+    hass: HomeAssistant, database: NestQuestDatabase
+) -> None:
+    """Materialize the rolling horizon ``[today, today + DEFAULT_HORIZON_DAYS]``.
+
+    "today" is computed in HA local time (``hass.config.time_zone``) rather
+    than the system clock, so the horizon tracks the household's own day.
+    The walk itself runs through :func:`~.materialize.materialize`, whose DB
+    access is executor-only.
+
+    This is the ONE generation path: the startup backfill, the daily rollover
+    listener and the ``regenerate`` service all funnel through it, so there is
+    no duplicated materialization logic.
+    """
+    time_zone = ZoneInfo(hass.config.time_zone)
+    today = datetime.datetime.now(time_zone).date()
+    start_date = today.isoformat()
+    end_date = (
+        today + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)
+    ).isoformat()
+    await _materialize_run(database, start_date, end_date, today=today)
+
+
 def _register_day_rollover_listener(
     hass: HomeAssistant,
     database: NestQuestDatabase,
@@ -280,28 +304,69 @@ def _register_day_rollover_listener(
     """Register the daily materialization listener and return its remover.
 
     Fires once per day at the configured local ``day_rollover_time`` and
-    materializes the rolling horizon ``[today, today + DEFAULT_HORIZON_DAYS]``.
-    "today" is computed in HA local time (``hass.config.time_zone``) rather
-    than the system clock, so the horizon tracks the household's own day.
-    The walk itself runs through :func:`~.materialize.materialize`, whose DB
-    access is executor-only.
+    materializes the rolling horizon ``[today, today + DEFAULT_HORIZON_DAYS]``
+    through the shared :func:`_run_horizon_materialization` path.
     """
     hour, minute = _day_rollover_hour_minute(options)
 
     async def _run_materialization(_now: datetime.datetime) -> None:
-        time_zone = ZoneInfo(hass.config.time_zone)
-        today = datetime.datetime.now(time_zone).date()
-        start_date = today.isoformat()
-        end_date = (
-            today + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)
-        ).isoformat()
-        await _materialize_run(database, start_date, end_date)
+        await _run_horizon_materialization(hass, database)
 
     return async_track_time_change(
         hass, _run_materialization, hour=hour, minute=minute
     )
 
 
+def _find_live_database(hass: HomeAssistant) -> NestQuestDatabase | None:
+    """Return a connected database from the active runtime data, or None.
+
+    The domain-global services (e.g. ``regenerate``) have no database of
+    their own; they resolve whichever config entry's database is currently
+    live at call time, so none of them can hold a stale handle to a closed
+    connection after another entry unloads.
+    """
+    for runtime_data in hass.data.get(DOMAIN, {}).values():
+        database = getattr(runtime_data, "database", None)
+        if database is not None and database.connected:
+            return database
+    return None
+
+
+def _register_regenerate_service(hass: HomeAssistant) -> None:
+    """Register ``nestquest.regenerate`` once at domain scope.
+
+    The service triggers a full on-demand regeneration over the rolling
+    horizon, running the SAME idempotent materialize path
+    (:func:`_run_horizon_materialization`) as the startup backfill and the
+    daily rollover listener.  It is DOMAIN-global — registered exactly once
+    (guarded by ``has_service``) and NOT bound to any config entry — so the
+    handler resolves the currently-live database at call time and a name
+    collision or duplicate setup is impossible.  Removal is handled by the
+    unload path only once the LAST entry is removed (see
+    :func:`_deregister_regenerate_service`).
+    """
+    if hass.services.has_service(DOMAIN, SERVICE_REGENERATE):
+        return
+
+    async def _regenerate(_call: Any) -> None:
+        database = _find_live_database(hass)
+        if database is None:
+            _LOGGER.warning(
+                "NestQuest regenerate requested but no config entry has a "
+                "live database; ignoring"
+            )
+            return
+        await _run_horizon_materialization(hass, database)
+
+    hass.services.async_register(DOMAIN, SERVICE_REGENERATE, _regenerate)
+
+
+def _deregister_regenerate_service(hass: HomeAssistant) -> None:
+    """Remove ``nestquest.regenerate`` when the last entry unloads."""
+    if hass.services.has_service(DOMAIN, SERVICE_REGENERATE):
+        hass.services.async_remove(DOMAIN, SERVICE_REGENERATE)
+
+
 async def async_setup(hass: HomeAssistant, config: dict[str, Any]) -> bool:
     """Set up the NestQuest integration. YAML configuration is not used, returns True."""
     return True
@@ -359,6 +424,8 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
         await listener_hass.config_entries.async_reload(listener_entry.entry_id)
 
     database = await _async_open_database(hass, await async_get_db_path(hass))
+    remove_update_listener: Callable[[], Any] | None = None
+    remove_time_change_listener: Callable[[], Any] | None = None
     try:
         # Seed the admin allowlist on first setup so the owner is never
         # locked out: an empty database takes the persisted admin copy
@@ -387,9 +454,34 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
         remove_time_change_listener = _register_day_rollover_listener(
             hass, database, dict(entry.options)
         )
+        # Backfill any days the daily listener missed while the integration
+        # was off (or freshly installed): run the one idempotent walk over
+        # [today, today + DEFAULT_HORIZON_DAYS] once at setup.  This runs
+        # through the SAME path as the daily listener and regenerate service.
+        await _run_horizon_materialization(hass, database)
+        _register_regenerate_service(hass)
     except BaseException:
+        # A failure anywhere after the database is open must not leak the
+        # listeners already registered against that (now-closed) database:
+        # unwind EVERY remover we acquired before the failure, keeping the
+        # original error as the one raised.  Removal is best-effort — a
+        # failing remover must not mask the setup error that triggered it.
+        for remove_listener in (
+            remove_time_change_listener,
+            remove_update_listener,
+        ):
+            if remove_listener is None:
+                continue
+            try:
+                result = remove_listener()
+                if inspect.isawaitable(result):
+                    await result
+            except BaseException:
+                pass
         await database.close()
         raise
+    assert remove_update_listener is not None
+    assert remove_time_change_listener is not None
     runtime_data = NestQuestRuntimeData(
         entry_id=entry.entry_id,
         options=dict(entry.options),
@@ -406,16 +498,17 @@ async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     """Unload a config entry."""
     domain_data = hass.data.setdefault(DOMAIN, {})
     runtime_data = domain_data.pop(entry.entry_id, None)
-    if not domain_data:
+    is_last = not domain_data
+    if is_last:
         hass.data.pop(DOMAIN, None)
     if runtime_data is None:
         runtime_data = getattr(entry, "runtime_data", None)
+    unload_error: BaseException | None = None
     if runtime_data is not None:
         remove_update_listener = getattr(runtime_data, "remove_update_listener", None)
         remove_time_change_listener = getattr(
             runtime_data, "remove_time_change_listener", None
         )
-        unload_error: BaseException | None = None
         try:
             for remove_listener in (
                 remove_update_listener,
@@ -439,10 +532,13 @@ async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
             database = getattr(runtime_data, "database", None)
             if database is not None:
                 await database.close()
-        if unload_error is not None:
-            if getattr(entry, "runtime_data", None) is not None:
-                entry.runtime_data = None
-            raise unload_error
+    # The ``regenerate`` service is DOMAIN-global: it is torn down only
+    # once the FINAL entry unloads (``hass.data[DOMAIN]`` is now empty),
+    # never when a sibling entry is still loaded.
+    if is_last:
+        _deregister_regenerate_service(hass)
     if getattr(entry, "runtime_data", None) is not None:
         entry.runtime_data = None
+    if unload_error is not None:
+        raise unload_error
     return True
diff --git a/custom_components/nestquest/const.py b/custom_components/nestquest/const.py
index 8167e53..ce21568 100644
--- a/custom_components/nestquest/const.py
+++ b/custom_components/nestquest/const.py
@@ -9,6 +9,9 @@ LOGGER = logging.getLogger(LOGGER_NAME)
 
 PLATFORMS: list[str] = []
 
+#: Service name for the on-demand regeneration service (``nestquest.regenerate``).
+SERVICE_REGENERATE = "regenerate"
+
 SQLITE_DB_FILENAME = "nestquest.db"
 
 # Configuration keys and default values
diff --git a/custom_components/nestquest/dao_instances.py b/custom_components/nestquest/dao_instances.py
index c948aa8..94f05b9 100644
--- a/custom_components/nestquest/dao_instances.py
+++ b/custom_components/nestquest/dao_instances.py
@@ -59,6 +59,34 @@ def _today() -> datetime.date:
     return datetime.date.today()
 
 
+def _resolve_today(today: datetime.date | None) -> datetime.date:
+    """Return the caller-resolved "today", or the host date when absent.
+
+    The no-past guard and the delete cutoffs must compare due dates
+    against the SAME calendar date the materialization horizon was built
+    from.  Home Assistant's configured time zone can lag the host clock
+    around midnight, so when the caller has already resolved the local
+    date (``today``) that anchor is authoritative; ``None`` falls back to
+    the host clock (:func:`_today`), which is exactly the previous
+    behavior for callers with no HA-local date.
+    """
+    return _today() if today is None else today
+
+
+def _reject_past(due_date: str, today_iso: str) -> None:
+    """Raise unless ``due_date`` is on or after ``today_iso``.
+
+    The single no-past rule shared by :meth:`QuestInstancesDao.upsert`
+    and :meth:`QuestInstancesDao.upsert_if_valid`: instances are never
+    generated in the past, measured against the resolved "today".
+    """
+    if due_date < today_iso:
+        raise ValueError(
+            f"instances are never generated in the past: due_date "
+            f"{due_date!r} is before today {today_iso!r}"
+        )
+
+
 def _validate_utc_timestamp(value: str, field: str) -> None:
     """Raise ValueError unless ``value`` is a strict UTC ISO-8601 stamp.
 
@@ -178,6 +206,7 @@ class QuestInstancesDao:
         *,
         window: str,
         due_time: str | None = None,
+        today: datetime.date | None = None,
     ) -> QuestInstanceRecord:
         """Create the dated instance for the widened key idempotently.
 
@@ -196,6 +225,10 @@ class QuestInstancesDao:
         - ``due_date`` must be TODAY or later: instances are never
           generated in the past (Feature 07).  The caller's
           materialization horizon is future-dated by definition.
+          ``today`` optionally pins the resolved HA-local date the
+          guard compares against (falling back to the host clock when
+          omitted) so a household time zone behind the host around
+          midnight is not misread as "past".
         - ``window`` must be one of ``const.QUEST_WINDOWS``.
         - An existing instance WITH a completion event is IMMUTABLE:
           the conflict path must not rewrite its snapshot columns
@@ -215,24 +248,20 @@ class QuestInstancesDao:
         # check runs after the lock is acquired, because a caller can
         # wait on the lock across midnight — a date that was "today"
         # at call time may be "yesterday" by the time the INSERT runs.
-        today = _today().isoformat()
-        if due_date < today:
-            raise ValueError(
-                f"instances are never generated in the past: due_date "
-                f"{due_date!r} is before today {today!r}"
-            )
+        # A caller-supplied ``today`` (HA-local) is used for BOTH
+        # checks and never re-read, since it is already the anchor the
+        # batch runs against.
+        today_date = _resolve_today(today)
+        _reject_past(due_date, today_date.isoformat())
         async with _connection_lock(self._database):
             async with self._database.transaction():
                 # Re-read "today" under the lock: this is the date the
                 # insert actually executes on, so the no-past rule
-                # holds across midnight rollovers.
-                today = _today().isoformat()
-                if due_date < today:
-                    raise ValueError(
-                        f"instances are never generated in the past: "
-                        f"due_date {due_date!r} is before today "
-                        f"{today!r}"
-                    )
+                # holds across midnight rollovers.  A pinned HA-local
+                # anchor is exempt from the re-read (see above).
+                if today is None:
+                    today_date = _today()
+                _reject_past(due_date, today_date.isoformat())
                 definition = await self._database.fetch_one(
                     "SELECT 1 FROM quest_definitions WHERE id = ?",
                     (definition_id,),
@@ -298,6 +327,7 @@ class QuestInstancesDao:
         *,
         window: str,
         due_time: str | None = None,
+        today: datetime.date | None = None,
     ) -> QuestInstanceRecord | None:
         """Insert one dated instance iff its tuple is still materializable.
 
@@ -327,7 +357,8 @@ class QuestInstancesDao:
         failed — the tuple no longer materializable, which the walk SKIPS
         rather than raising, so the rest of the batch is unaffected.  The
         no-past rule (instances are never generated in the past) is
-        preserved from :meth:`upsert` and still raises ValueError.  An
+        preserved from :meth:`upsert` and still raises ValueError; ``today``
+        optionally pins the HA-local anchor it compares against.  An
         instance that ALREADY has a completion event is also skipped
         (returns ``None``) rather than raised: it is immutable, so the
         walk leaves it untouched instead of failing the batch — the
@@ -338,20 +369,13 @@ class QuestInstancesDao:
         _validate_window(window)
         # Fail fast on obviously-past dates before queuing on the lock;
         # the authoritative check re-runs under the lock (see upsert).
-        today = _today().isoformat()
-        if due_date < today:
-            raise ValueError(
-                f"instances are never generated in the past: due_date "
-                f"{due_date!r} is before today {today!r}"
-            )
+        today_date = _resolve_today(today)
+        _reject_past(due_date, today_date.isoformat())
         async with _connection_lock(self._database):
             async with self._database.transaction():
-                today = _today().isoformat()
-                if due_date < today:
-                    raise ValueError(
-                        f"instances are never generated in the past: "
-                        f"due_date {due_date!r} is before today {today!r}"
-                    )
+                if today is None:
+                    today_date = _today()
+                _reject_past(due_date, today_date.isoformat())
                 still_valid = await self._database.fetch_one(
                     "SELECT 1 FROM quest_definitions d "
                     "JOIN quest_definition_assignees a "
@@ -463,7 +487,7 @@ class QuestInstancesDao:
         return [_instance_from_row(row) for row in rows]
 
     async def delete_future_uncompleted(
-        self, definition_id: int, cutoff_date: str
+        self, definition_id: int, cutoff_date: str, *, today: datetime.date | None = None
     ) -> int:
         """Delete the definition's open instances at/after cutoff.
 
@@ -475,9 +499,11 @@ class QuestInstancesDao:
         is measured against TODAY (materialization regenerates the
         rolling horizon from now), so a caller cannot use this to
         rewrite past open instances either — the day-rollover missed
-        sweep (Feature 11) handles past-due instances instead.  Any
-        instance with a completion event is never touched, regardless
-        of its date.  Returns the number deleted.
+        sweep (Feature 11) handles past-due instances instead.  ``today``
+        optionally pins the HA-local anchor the clamp compares against
+        (falling back to the host clock when omitted).  Any instance with
+        a completion event is never touched, regardless of its date.
+        Returns the number deleted.
         """
         _validate_date(cutoff_date, "cutoff_date")
         async with _connection_lock(self._database):
@@ -487,8 +513,8 @@ class QuestInstancesDao:
                 # midnight cannot delete instances that became past
                 # while it waited (backdating is clamped to the
                 # execution date, not the call date).
-                today = _today().isoformat()
-                effective_cutoff = max(cutoff_date, today)
+                today_date = _resolve_today(today)
+                effective_cutoff = max(cutoff_date, today_date.isoformat())
                 result = await self._database.execute(
                     "DELETE FROM quest_instances WHERE definition_id = ? "
                     "AND due_date >= ? AND NOT EXISTS ("
@@ -500,7 +526,7 @@ class QuestInstancesDao:
         return result.rowcount
 
     async def delete_future_uncompleted_for_child(
-        self, child_id: int, cutoff_date: str
+        self, child_id: int, cutoff_date: str, *, today: datetime.date | None = None
     ) -> tuple[int, str]:
         """Delete the child's open instances at/after cutoff, across every
         definition, returning ``(deleted, effective_cutoff)``.
@@ -511,8 +537,10 @@ class QuestInstancesDao:
         one transaction — an instance that gains a completion event
         mid-flight cannot be deleted.  The cutoff cannot be backdated below
         today, for the same reason as the definition-scoped method (see its
-        docstring).  Any instance with a completion event is never touched,
-        regardless of its date.
+        docstring).  ``today`` optionally pins the HA-local anchor the clamp
+        compares against (falling back to the host clock when omitted).
+        Any instance with a completion event is never touched, regardless
+        of its date.
 
         Returns the number deleted and the effective cutoff that was
         actually applied (``max(cutoff_date, today)``, read under the
@@ -530,8 +558,8 @@ class QuestInstancesDao:
                 # definition-scoped method: the DELETE executes on this
                 # date, so a caller queued across midnight cannot delete
                 # instances that became past while it waited.
-                today = _today().isoformat()
-                effective_cutoff = max(cutoff_date, today)
+                today_date = _resolve_today(today)
+                effective_cutoff = max(cutoff_date, today_date.isoformat())
                 result = await self._database.execute(
                     "DELETE FROM quest_instances WHERE child_id = ? "
                     "AND due_date >= ? AND NOT EXISTS ("
diff --git a/custom_components/nestquest/materialize.py b/custom_components/nestquest/materialize.py
index 342e626..3f22e07 100644
--- a/custom_components/nestquest/materialize.py
+++ b/custom_components/nestquest/materialize.py
@@ -64,7 +64,7 @@ from __future__ import annotations
 import datetime
 
 from .const import DEFAULT_HORIZON_DAYS
-from .dao_instances import QuestInstancesDao, _today
+from .dao_instances import QuestInstancesDao, _resolve_today
 from .dao_rules import (
     _validate_date,
     load_materialization_input,
@@ -127,6 +127,7 @@ async def materialize(
     end_date: str,
     *,
     child_ids: list[int] | None = None,
+    today: datetime.date | None = None,
 ) -> int:
     """Generate quest instances for the closed range [start_date, end_date].
 
@@ -142,6 +143,14 @@ async def materialize(
     after a presence change) cannot touch any unrelated child's rows.
     When omitted (or None) the walk covers every assignee as before.
 
+    ``today`` optionally pins the resolved HA-local date the walk's
+    no-past guard compares against; it is threaded into every
+    :meth:`~.dao_instances.QuestInstancesDao.upsert_if_valid` write.  When
+    omitted the host clock (``datetime.date.today``) is used, which is the
+    historical default.  A caller that computed the horizon in Home
+    Assistant's configured time zone MUST pass that same date here so a
+    time zone behind the host around midnight is not rejected as "past".
+
     All inputs are read in ONE locked transaction; each tuple's write then
     goes through the atomic :meth:`~.dao_instances.QuestInstancesDao.upsert_if_valid`,
     which re-validates the tuple and its current ``due_time`` in the same
@@ -195,6 +204,7 @@ async def materialize(
                         generated_at,
                         window=window.window,
                         due_time=window.due_time,
+                        today=today,
                     )
                     if written is not None:
                         count += 1
@@ -205,6 +215,8 @@ async def materialize(
 async def regenerate_for_definition(
     database: NestQuestDatabase,
     definition_id: int,
+    *,
+    today: datetime.date | None = None,
 ) -> int:
     """Regenerate a definition's future instances after a config change.
 
@@ -221,17 +233,24 @@ async def regenerate_for_definition(
     :func:`~.dao_instances._today` — so the delete cutoff and the
     re-materialization range share one anchor, and the walk's
     ``upsert_if_valid`` no-past guard never rejects the regenerated
-    range.  Returns the number of instances the re-materialization
+    range.  ``today`` optionally pins a caller-resolved HA-local date
+    (threaded into both the delete cutoff and the re-materialization)
+    so a household time zone behind the host around midnight stays
+    consistent.  Returns the number of instances the re-materialization
     upserted across the whole snapshot (idempotent — other active
     definitions' tuples refresh in place, never duplicate).
     """
-    today = _today()
-    start_date = today.isoformat()
-    end_date = (today + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)).isoformat()
+    today_date = _resolve_today(today)
+    start_date = today_date.isoformat()
+    end_date = (
+        today_date + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)
+    ).isoformat()
 
     instances = QuestInstancesDao(database)
-    await instances.delete_future_uncompleted(definition_id, start_date)
-    return await materialize(database, start_date, end_date)
+    await instances.delete_future_uncompleted(
+        definition_id, start_date, today=today
+    )
+    return await materialize(database, start_date, end_date, today=today)
 
 
 # HOOK (Feature 09 presence services): ``regenerate_for_child`` is the
@@ -250,6 +269,8 @@ async def regenerate_for_definition(
 async def regenerate_for_child(
     database: NestQuestDatabase,
     child_id: int,
+    *,
+    today: datetime.date | None = None,
 ) -> int:
     """Regenerate a child's future instances after a presence change.
 
@@ -277,13 +298,16 @@ async def regenerate_for_child(
     :meth:`~.dao_instances.QuestInstancesDao.delete_future_uncompleted_for_child`),
     so the delete cutoff and the re-materialization window share ONE
     execution-day anchor even when the call is queued across midnight.
-    Returns the number of instances the re-materialization upserted for
-    the child across the whole snapshot.
+    ``today`` optionally pins a caller-resolved HA-local date, threaded
+    into the delete cutoff and the re-materialization for the same
+    host-vs-HA time-zone consistency.  Returns the number of instances
+    the re-materialization upserted for the child across the whole
+    snapshot.
     """
     if isinstance(child_id, bool) or not isinstance(child_id, int):
         raise ValueError(f"child_id must be an integer, got {child_id!r}")
 
-    today = _today()
+    today_date = _resolve_today(today)
 
     instances = QuestInstancesDao(database)
     # Use the delete's returned effective cutoff as the materialize anchor,
@@ -293,10 +317,10 @@ async def regenerate_for_child(
     # walk's no-past guard and leave the child's future instances deleted
     # but not rebuilt.  One anchor for both keeps them consistent.
     _, effective_cutoff = await instances.delete_future_uncompleted_for_child(
-        child_id, today.isoformat()
+        child_id, today_date.isoformat(), today=today
     )
     start = datetime.date.fromisoformat(effective_cutoff)
     end_date = (start + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)).isoformat()
     return await materialize(
-        database, start.isoformat(), end_date, child_ids=[child_id]
+        database, start.isoformat(), end_date, child_ids=[child_id], today=today
     )
diff --git a/custom_components/nestquest/services.yaml b/custom_components/nestquest/services.yaml
new file mode 100644
index 0000000..eeae053
--- /dev/null
+++ b/custom_components/nestquest/services.yaml
@@ -0,0 +1,12 @@
+# Service declarations for the NestQuest integration (Home Assistant
+# services.yaml metadata). Services are domain-scoped: nested under the
+# "nestquest" domain, not repeated per config entry.
+
+regenerate:
+  name: Regenerate quest instances
+  description: >-
+    Regenerate every future quest instance for the household over the rolling
+    horizon, using the same idempotent materialization as the daily rollover
+    and the startup backfill. Safe to call at any time: a re-run refreshes the
+    same rows instead of duplicating them, and completed instances are never
+    touched.
\ No newline at end of file
diff --git a/tests/conftest.py b/tests/conftest.py
index ff8c5d6..b6603e8 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -307,6 +307,50 @@ def _async_track_time_change(hass, action, hour=None, minute=None, second=None):
 _ha_mock("homeassistant.helpers.event").async_track_time_change = _async_track_time_change
 
 
+class ServiceRegistry:
+    """Models HA's ``hass.services`` service registry.
+
+    ``async_register`` stores a handler under its (domain, service) key,
+    ``has_service`` reports registration, and ``async_remove`` removes it
+    — exactly the surface Home Assistant's ``ServiceRegistry`` exposes
+    (there is deliberately NO ``async_unregister`` alias here, so a caller
+    that uses the wrong method name fails instead of being silently
+    papered over).  ``call`` invokes a stored handler the way HA's service
+    bus would — awaiting a coroutine result — so tests can exercise a
+    registered service end-to-end.
+    """
+
+    def __init__(self, hass=None):
+        self._hass = hass
+        self._services: dict[tuple[str, str], object] = {}
+
+    def async_register(self, domain, service, func, schema=None, supports_response=None):
+        self._services[(domain, service)] = func
+        return None
+
+    def has_service(self, domain, service):
+        return (domain, service) in self._services
+
+    def async_remove(self, domain, service):
+        self._services.pop((domain, service), None)
+        return None
+
+    async def call(self, domain, service, data=None):
+        func = self._services.get((domain, service))
+        if func is None:
+            raise KeyError(f"service {domain}.{service} not registered")
+        call = SimpleNamespace(domain=domain, service=service, data=data or {})
+        result = func(call)
+        if inspect.isawaitable(result):
+            await result
+        return result
+
+    @property
+    def registered_services(self):
+        """The registered (domain, service) pairs."""
+        return list(self._services)
+
+
 def make_config_entry(
     entry_id: str = "test_entry",
     options: dict | None = None,
@@ -369,6 +413,7 @@ def make_hass() -> tuple:
     hass.async_add_executor_job = _run_executor_job
     registry = ListenerRegistry(hass)
     hass.time_change = TimeChangeRegistry(hass)
+    hass.services = ServiceRegistry(hass)
     # A valid IANA time zone (the day-rollover listener reads it to
     # compute "today" in HA local time).
     hass.config.time_zone = "UTC"
diff --git a/tests/test_lifecycle.py b/tests/test_lifecycle.py
index f56864f..68be6ce 100644
--- a/tests/test_lifecycle.py
+++ b/tests/test_lifecycle.py
@@ -11,6 +11,7 @@ from custom_components.nestquest import DOMAIN, async_setup_entry, async_unload_
 from custom_components.nestquest.const import (
     CONF_DAY_ROLLOVER_TIME,
     DEFAULT_HORIZON_DAYS,
+    SERVICE_REGENERATE,
     DOMAIN as DOMAIN_CONST,
 )
 
@@ -345,7 +346,9 @@ async def test_day_rollover_listener_materializes_ha_local_horizon(
 
     await hass.time_change.fire()
 
-    fake.assert_awaited_once_with(database, expected_start, expected_end)
+    fake.assert_awaited_once_with(
+        database, expected_start, expected_end, today=today
+    )
 
 
 def test_day_rollover_time_change_tracker_rejects_local_kwarg() -> None:
@@ -381,4 +384,173 @@ async def test_setup_applies_all_v1_tables(hass, make_entry) -> None:
         "quest_definitions",
         "schedule_rules",
     ]
-    await async_unload_entry(hass, entry)
\ No newline at end of file
+    await async_unload_entry(hass, entry)
+
+
+async def _seed_daily_child_and_definition(database, today) -> int:
+    """Create one always-present child + a daily definition starting today.
+
+    Returns the child's id.  No presence schedule means the child is present
+    every day, so the daily rule yields exactly one instance per horizon day.
+    """
+    from custom_components.nestquest.dao_children import ChildrenDao
+    from custom_components.nestquest.quest_definitions import (
+        create_quest_definition,
+    )
+    from custom_components.nestquest.recurrence import RuleType, ScheduleRule
+
+    NOW = "2026-09-14T12:00:00+00:00"
+    child = await ChildrenDao(database).create("Ada", NOW)
+    await create_quest_definition(
+        database,
+        "Daily chore",
+        ScheduleRule(rule_type=RuleType.DAILY, start_date=today.isoformat()),
+        [child.id],
+        ["morning"],
+    )
+    return child.id
+
+
+def _local_today(hass) -> "datetime.date":
+    import datetime
+    from zoneinfo import ZoneInfo
+
+    return datetime.datetime.now(ZoneInfo(hass.config.time_zone)).date()
+
+
+async def test_setup_backfills_instances_over_horizon(hass, make_entry) -> None:
+    """Setup materializes once so a restart backfills any missed days."""
+    import datetime
+
+    from custom_components.nestquest.dao_instances import QuestInstancesDao
+    from custom_components.nestquest.db import NestQuestDatabase
+    from custom_components.nestquest.migrations import apply_migrations
+    from custom_components.nestquest.store import async_get_db_path
+
+    # Seed the database BEFORE setup: a restart reopens an existing file that
+    # already holds definitions.  The startup backfill must pick them up.
+    db_path = await async_get_db_path(hass)
+    pre = NestQuestDatabase(hass)
+    await pre.open(db_path)
+    await apply_migrations(pre)
+    child_id = await _seed_daily_child_and_definition(pre, _local_today(hass))
+    await pre.close()
+
+    entry = _wire(make_entry(), hass.registry)
+    assert await async_setup_entry(hass, entry) is True
+
+    today = _local_today(hass)
+    end = (today + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)).isoformat()
+    records = await QuestInstancesDao(entry.runtime_data.database).list_by_date_range(
+        child_id, today.isoformat(), end
+    )
+    assert len(records) == DEFAULT_HORIZON_DAYS + 1
+
+
+async def test_regenerate_service_registered_and_materializes(
+    hass, make_entry
+) -> None:
+    """``nestquest.regenerate`` is registered and calling it regenerates."""
+    import datetime
+
+    from custom_components.nestquest.dao_instances import QuestInstancesDao
+
+    entry = _wire(make_entry(), hass.registry)
+    assert await async_setup_entry(hass, entry) is True
+    assert hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+
+    # A definition created AFTER setup has no instances yet (create does not
+    # materialize); the service must generate them on demand.
+    database = entry.runtime_data.database
+    child_id = await _seed_daily_child_and_definition(database, _local_today(hass))
+
+    await hass.services.call(DOMAIN, SERVICE_REGENERATE)
+
+    today = _local_today(hass)
+    end = (today + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)).isoformat()
+    records = await QuestInstancesDao(database).list_by_date_range(
+        child_id, today.isoformat(), end
+    )
+    assert len(records) == DEFAULT_HORIZON_DAYS + 1
+
+
+async def test_unload_deregisters_regenerate_service(hass, make_entry) -> None:
+    """Unload removes the ``regenerate`` service so no stale entry leaks."""
+    entry = _wire(make_entry(), hass.registry)
+    assert await async_setup_entry(hass, entry) is True
+    assert hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+
+    assert await async_unload_entry(hass, entry) is True
+    assert not hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+
+
+async def test_regenerate_service_is_domain_scoped_across_entries(
+    hass, make_entry
+) -> None:
+    """The ``regenerate`` service is domain-global, not per-entry.
+
+    With two loaded entries the service must be registered and functional;
+    unloading one entry must keep it registered and functional for the
+    remaining entry; unloading the final entry must remove it.
+    """
+    import datetime
+
+    from custom_components.nestquest.dao_instances import QuestInstancesDao
+
+    entry_a = _wire(make_entry(entry_id="entry_a"), hass.registry)
+    entry_b = _wire(make_entry(entry_id="entry_b"), hass.registry)
+
+    assert await async_setup_entry(hass, entry_a) is True
+    assert await async_setup_entry(hass, entry_b) is True
+    assert hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+
+    # The domain-global handler resolves a live database from any entry.
+    database_b = entry_b.runtime_data.database
+    child_id = await _seed_daily_child_and_definition(
+        database_b, _local_today(hass)
+    )
+    await hass.services.call(DOMAIN, SERVICE_REGENERATE)
+    today = _local_today(hass)
+    end = (today + datetime.timedelta(days=DEFAULT_HORIZON_DAYS)).isoformat()
+    records = await QuestInstancesDao(database_b).list_by_date_range(
+        child_id, today.isoformat(), end
+    )
+    assert len(records) == DEFAULT_HORIZON_DAYS + 1
+
+    # Unloading one entry must not tear down the shared service.
+    assert await async_unload_entry(hass, entry_a) is True
+    assert hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+
+    # It still works for the remaining entry.
+    await hass.services.call(DOMAIN, SERVICE_REGENERATE)
+
+    # Unloading the final entry removes the domain-global service.
+    assert await async_unload_entry(hass, entry_b) is True
+    assert not hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+
+
+async def test_setup_cleans_listeners_when_materialization_raises(
+    hass, make_entry, monkeypatch
+) -> None:
+    """A startup-materialization failure rolls back every registered listener.
+
+    The daily and update listeners are installed before the startup
+    materialization runs; when that walk raises, the database is closed but
+    the remover callables must also be invoked so no listener survives
+    firing against a closed database.
+    """
+    import custom_components.nestquest as nestquest
+
+    async def _boom(*_args, **_kwargs):
+        raise RuntimeError("materialization failed")
+
+    monkeypatch.setattr(nestquest, "_materialize_run", _boom)
+
+    entry = _wire(make_entry(), hass.registry)
+    with pytest.raises(RuntimeError, match="materialization failed"):
+        await async_setup_entry(hass, entry)
+
+    assert hass.time_change.size == 0
+    assert hass.registry.size == 0
+    assert not hass.services.has_service(DOMAIN, SERVICE_REGENERATE)
+    assert not hasattr(entry, "runtime_data")
\ No newline at end of file
diff --git a/tests/test_materialize.py b/tests/test_materialize.py
index 62523fd..c20f226 100644
--- a/tests/test_materialize.py
+++ b/tests/test_materialize.py
@@ -340,7 +340,7 @@ async def _materialize_with_change(
     seen = {"n": 0}
 
     async def _gated(self, definition_id, child_id, due_date, generated_at,
-                     *, window, due_time=None):
+                     *, window, due_time=None, today=None):
         seen["n"] += 1
         if seen["n"] == 1:
             seen["first"] = (definition_id, child_id, window)
@@ -348,7 +348,7 @@ async def _materialize_with_change(
             await release.wait()
         return await original_upsert(
             self, definition_id, child_id, due_date, generated_at,
-            window=window, due_time=due_time,
+            window=window, due_time=due_time, today=today,
         )
 
     QuestInstancesDao.upsert_if_valid = _gated
@@ -630,6 +630,42 @@ def test_materialize_rejects_malformed_or_inverted_bounds(tmp_path) -> None:
     _with_db(tmp_path, "materialize-bounds.db")(_body)
 
 
+def test_materialize_accepts_ha_local_today_behind_host(tmp_path) -> None:
+    """The no-past guard compares against a caller-supplied HA-local today.
+
+    A household time zone behind the host clock around midnight resolves a
+    HA-local "today" one calendar day earlier than the host's
+    ``date.today()``.  The host-clock guard would reject that date as past,
+    so the resolved HA-local date must be threaded through ``materialize``
+    and accepted instead of raising.
+    """
+    async def _body(database):
+        children = ChildrenDao(database)
+        child = await children.create("Ada", NOW)
+        ha_today = datetime.date.today() - datetime.timedelta(days=1)
+        start_iso = ha_today.isoformat()
+        end_iso = (ha_today + datetime.timedelta(days=14)).isoformat()
+        await create_quest_definition(
+            database,
+            "Daily chore",
+            ScheduleRule(rule_type=RuleType.DAILY, start_date=start_iso),
+            [child.id],
+            ["morning"],
+        )
+
+        # Without the pinned HA-local today, the host-clock guard rejects
+        # the horizon start (ha_today is "yesterday" on the host).
+        with pytest.raises(ValueError, match="never generated in the past"):
+            await materialize(database, start_iso, end_iso)
+
+        # With today=ha_today, the same range is accepted and materialized.
+        count = await materialize(database, start_iso, end_iso, today=ha_today)
+        assert count == 15
+        return count
+
+    _with_db(tmp_path, "materialize-ha-local-today.db")(_body)
+
+
 def test_materialize_skips_inactive_definitions(tmp_path) -> None:
     async def _body(database):
         from custom_components.nestquest.quest_definitions import (
@@ -914,10 +950,8 @@ def test_regenerate_for_child_uses_single_anchor_across_midnight(
         return day0 if clock["reads"] == 1 else day1
 
     import custom_components.nestquest.dao_instances as dao_instances_module
-    import custom_components.nestquest.materialize as materialize_module
 
     monkeypatch.setattr(dao_instances_module, "_today", _fake_today)
-    monkeypatch.setattr(materialize_module, "_today", _fake_today)
 
     async def _body(database):
         children = ChildrenDao(database)
diff --git a/tests/test_services.py b/tests/test_services.py
new file mode 100644
index 0000000..68f2cde
--- /dev/null
+++ b/tests/test_services.py
@@ -0,0 +1,41 @@
+"""Tests for the NestQuest services.yaml declaration file."""
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+SERVICES_PATH = (
+    Path(__file__).parent.parent
+    / "custom_components"
+    / "nestquest"
+    / "services.yaml"
+)
+
+
+def test_services_yaml_exists() -> None:
+    assert SERVICES_PATH.exists(), f"services.yaml missing at {SERVICES_PATH}"
+
+
+def test_services_yaml_declares_regenerate() -> None:
+    text = SERVICES_PATH.read_text(encoding="utf-8")
+    assert re.search(r"^regenerate:\s*$", text, re.MULTILINE), (
+        "services.yaml must declare the 'regenerate' service"
+    )
+
+
+def test_services_yaml_regenerate_has_description_and_no_fields() -> None:
+    """The regenerate service is documented with a clear description and no
+    required fields (there is no ``fields`` block under it)."""
+    text = SERVICES_PATH.read_text(encoding="utf-8")
+    match = re.search(r"^regenerate:\s*$", text, re.MULTILINE)
+    assert match is not None
+    section = text[match.end():]
+    next_service = re.search(r"^(?![#\s])\w+:\s*$", section, re.MULTILINE)
+    if next_service is not None:
+        section = section[: next_service.start()]
+    assert re.search(r"description:", section), (
+        "regenerate must carry a description"
+    )
+    assert "fields:" not in section, (
+        "regenerate declares no required fields"
+    )
\ No newline at end of file