fix(quota-planner): normalize datetimes before database use

app/modules/quota_planner/repository.py

@@ -7,7 +7,7 @@
 from sqlalchemy import Integer, and_, cast, func, literal, select, update
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from app.core.utils.time import utcnow
+from app.core.utils.time import to_utc_naive, utcnow
 from app.db.models import (
     Account,
     QuotaPlannerDecision,
@@ -100,8 +100,8 @@ async def log_decision(
             mode=mode,
             action=action,
             account_id=account_id,
-            scheduled_at=scheduled_at,
-            executed_at=executed_at,
+            scheduled_at=_quota_planner_db_timestamp(scheduled_at),
+            executed_at=_quota_planner_db_timestamp(executed_at),
             score=score,
             reason=reason,
             forecast_snapshot_hash=forecast_snapshot_hash,
@@ -138,7 +138,7 @@ async def update_decision_status(
         if reason is not None:
             values["reason"] = reason
         if executed_at is not None:
-            values["executed_at"] = executed_at
+            values["executed_at"] = _quota_planner_db_timestamp(executed_at)
         if state_after_json is not None:
             values["state_after_json"] = state_after_json
         stmt = update(QuotaPlannerDecision).where(QuotaPlannerDecision.id == decision_id).values(**values)
@@ -160,6 +160,7 @@ async def update_decision_status(
         return row
 
     async def count_executed_warmups_since(self, since: datetime) -> int:
+        since = to_utc_naive(since)
         stmt = select(func.count(QuotaPlannerDecision.id)).where(
             and_(
                 QuotaPlannerDecision.action == "warmup",
@@ -170,6 +171,7 @@ async def count_executed_warmups_since(self, since: datetime) -> int:
         return int(await self._session.scalar(stmt) or 0)
 
     async def warmup_cost_since(self, since: datetime) -> float:
+        since = to_utc_naive(since)
         stmt = select(func.coalesce(func.sum(RequestLog.cost_usd), 0.0)).where(
             and_(
                 RequestLog.request_kind == "warmup",
@@ -215,7 +217,7 @@ async def add_window_observation(
     ) -> QuotaWindowObservation:
         row = QuotaWindowObservation(
             account_id=account_id,
-            observed_at=observed_at or utcnow(),
+            observed_at=_quota_planner_db_timestamp(observed_at) or utcnow(),
             model=model,
             primary_remaining_percent=primary_remaining_percent,
             primary_reset_at=primary_reset_at,
@@ -236,7 +238,7 @@ async def aggregate_demand_bins(
         since: datetime | None = None,
         bucket_seconds: int = 900,
     ) -> list[DemandBin]:
-        since = since or (utcnow() - timedelta(days=28))
+        since = to_utc_naive(since) if since is not None else (utcnow() - timedelta(days=28))
         bind = self._session.get_bind()
         dialect = bind.dialect.name if bind else "sqlite"
         if dialect == "postgresql":
@@ -296,6 +298,12 @@ async def aggregate_demand_bins(
         ]
 
 
+def _quota_planner_db_timestamp(value: datetime | None) -> datetime | None:
+    if value is None:
+        return None
+    return to_utc_naive(value)
+
+
 def _settings_from_row(row: QuotaPlannerSettings) -> PlannerSettings:
     return PlannerSettings(
         mode=row.mode,

tests/unit/test_quota_planner.py

@@ -18,7 +18,7 @@
     plan_shadow_actions,
     simulate_pool,
 )
-from app.modules.quota_planner.repository import DemandBin
+from app.modules.quota_planner.repository import DemandBin, _quota_planner_db_timestamp
 
 pytestmark = pytest.mark.unit
 
@@ -92,6 +92,13 @@ def test_planner_settings_default_to_nonblocking_shadow_mode() -> None:
     assert settings.dry_run is True
 
 
+def test_quota_planner_db_timestamp_normalizes_aware_datetimes_to_naive_utc() -> None:
+    scheduled_at = datetime(2026, 6, 18, 8, 30, tzinfo=timezone(timedelta(hours=3)))
+
+    assert _quota_planner_db_timestamp(scheduled_at) == datetime(2026, 6, 18, 5, 30)
+    assert _quota_planner_db_timestamp(None) is None
+
+
 def test_candidate_start_times_do_not_floor_now_into_the_past() -> None:
     settings = PlannerSettings(
         mode="shadow",