diff --git a/server/src/mcp/resources.ts b/server/src/mcp/resources.ts
index da8454523..03c165a78 100644
--- a/server/src/mcp/resources.ts
+++ b/server/src/mcp/resources.ts
@@ -60,7 +60,7 @@ export function registerResources(server: McpServer, userId: number, scopes: str
   // src/nest/reservations/reservations.mcp.ts (@ResourceTemplate).
 
   // The day-notes resource moved to the DI-discovered
-  // src/nest/days/day-notes.mcp.ts (@ResourceTemplate).
+  // src/nest/day-notes/day-notes.mcp.ts (@ResourceTemplate).
 
   // The trip-accommodations resource moved to the DI-discovered
   // src/nest/days/days.mcp.ts (@ResourceTemplate).
diff --git a/server/src/nest/app.module.ts b/server/src/nest/app.module.ts
index a91ccada9..db12f8d87 100644
--- a/server/src/nest/app.module.ts
+++ b/server/src/nest/app.module.ts
@@ -21,6 +21,7 @@ import { PackingModule } from './packing/packing.module';
 import { BudgetModule } from './budget/budget.module';
 import { ReservationsModule } from './reservations/reservations.module';
 import { DaysModule } from './days/days.module';
+import { DayNotesModule } from './day-notes/day-notes.module';
 import { AssignmentsModule } from './assignments/assignments.module';
 import { PlacesModule } from './places/places.module';
 import { TripsModule } from './trips/trips.module';
@@ -60,7 +61,7 @@ import { IdempotencyInterceptor } from './common/idempotency.interceptor';
  * migrated.
  */
 @Module({
-  imports: [AppConfigModule, DatabaseModule, RealtimeModule, McpModule.forRoot({ accessPolicy: trekMcpAccessPolicy, validateAccess: trekMcpValidateAccess }), HealthModule, WeatherModule, HelpModule, AirportsModule, ConfigModule, SystemNoticesModule, MapsModule, PlaceEnrichmentModule, CategoriesModule, TagsModule, NotificationsModule, AtlasModule, VacayModule, PackingModule, TodoModule, BudgetModule, ReservationsModule, DaysModule, AssignmentsModule, PlacesModule, TripsModule, CollabModule, FilesModule, PhotosModule, MemoriesModule, AirtrailModule, JourneyModule, CollectionsModule, ShareModule, TripInviteModule, TransitModule, FeedsModule, SettingsModule, BackupModule, AuthModule, OidcModule, OauthModule, AdminModule, AddonsModule, AuditModule, PermissionsModule, PluginsModule, BookingImportModule, LlmParseModule],
+  imports: [AppConfigModule, DatabaseModule, RealtimeModule, McpModule.forRoot({ accessPolicy: trekMcpAccessPolicy, validateAccess: trekMcpValidateAccess }), HealthModule, WeatherModule, HelpModule, AirportsModule, ConfigModule, SystemNoticesModule, MapsModule, PlaceEnrichmentModule, CategoriesModule, TagsModule, NotificationsModule, AtlasModule, VacayModule, PackingModule, TodoModule, BudgetModule, ReservationsModule, DaysModule, DayNotesModule, AssignmentsModule, PlacesModule, TripsModule, CollabModule, FilesModule, PhotosModule, MemoriesModule, AirtrailModule, JourneyModule, CollectionsModule, ShareModule, TripInviteModule, TransitModule, FeedsModule, SettingsModule, BackupModule, AuthModule, OidcModule, OauthModule, AdminModule, AddonsModule, AuditModule, PermissionsModule, PluginsModule, BookingImportModule, LlmParseModule],
   providers: [
     // Global error-envelope normaliser (DI-registered so it also catches
     // framework-level exceptions like the not-found handler).
diff --git a/server/src/nest/days/day-notes.controller.ts b/server/src/nest/day-notes/day-notes.controller.ts
similarity index 100%
rename from server/src/nest/days/day-notes.controller.ts
rename to server/src/nest/day-notes/day-notes.controller.ts
diff --git a/server/src/nest/days/day-notes.dto.ts b/server/src/nest/day-notes/day-notes.dto.ts
similarity index 100%
rename from server/src/nest/days/day-notes.dto.ts
rename to server/src/nest/day-notes/day-notes.dto.ts
diff --git a/server/src/nest/days/day-notes.mcp.ts b/server/src/nest/day-notes/day-notes.mcp.ts
similarity index 100%
rename from server/src/nest/days/day-notes.mcp.ts
rename to server/src/nest/day-notes/day-notes.mcp.ts
diff --git a/server/src/nest/day-notes/day-notes.module.ts b/server/src/nest/day-notes/day-notes.module.ts
new file mode 100644
index 000000000..8a3f55446
--- /dev/null
+++ b/server/src/nest/day-notes/day-notes.module.ts
@@ -0,0 +1,28 @@
+import { Module } from '@nestjs/common';
+import { DayNotesController } from './day-notes.controller';
+import { DayNotesService } from './day-notes.service';
+import { DayNotesMcp } from './day-notes.mcp';
+import { DayNotesRpc } from './day-notes.rpc';
+import { PermissionsModule } from '../permissions/permissions.module';
+import { AuthModule } from '../auth/auth.module';
+import { RealtimeModule } from '../realtime/realtime.module';
+import { PluginGuardsModule } from '../plugins/host/plugin-guards.module';
+
+/**
+ * Day notes. Its own domain rather than a second file set inside days/, which
+ * carried two fachlichkeiten with a full controller/service/mcp/rpc/dto each.
+ *
+ * Deliberately unconnected to DaysModule in both directions: `dayExists` is raw
+ * SQL on `days` here, and DaysService reads `day_notes` the same way. Wiring the
+ * modules to each other would buy nothing and cost a cycle.
+ *
+ * AuthModule is only for DayNotesMcp's demo-user gate, PluginGuardsModule only
+ * for DayNotesRpc.
+ */
+@Module({
+  imports: [PermissionsModule, AuthModule, RealtimeModule, PluginGuardsModule],
+  controllers: [DayNotesController],
+  providers: [DayNotesService, DayNotesMcp, DayNotesRpc],
+  exports: [DayNotesService],
+})
+export class DayNotesModule {}
diff --git a/server/src/nest/days/day-notes.rpc.ts b/server/src/nest/day-notes/day-notes.rpc.ts
similarity index 100%
rename from server/src/nest/days/day-notes.rpc.ts
rename to server/src/nest/day-notes/day-notes.rpc.ts
diff --git a/server/src/nest/days/day-notes.service.ts b/server/src/nest/day-notes/day-notes.service.ts
similarity index 100%
rename from server/src/nest/days/day-notes.service.ts
rename to server/src/nest/day-notes/day-notes.service.ts
diff --git a/server/src/nest/days/days.module.ts b/server/src/nest/days/days.module.ts
index 5bdb9b4a0..c3ed54524 100644
--- a/server/src/nest/days/days.module.ts
+++ b/server/src/nest/days/days.module.ts
@@ -2,32 +2,28 @@ import { Module } from '@nestjs/common';
 import { DaysController } from './days.controller';
 import { DaysService } from './days.service';
 import { DaysMcp } from './days.mcp';
-import { DayNotesController } from './day-notes.controller';
-import { DayNotesService } from './day-notes.service';
-import { DayNotesRpc } from './day-notes.rpc';
 import { DaysRpc } from './days.rpc';
 import { AccommodationsRpc } from './accommodations.rpc';
 import { PluginGuardsModule } from '../plugins/host/plugin-guards.module';
 import { RealtimeModule } from '../realtime/realtime.module';
-import { DayNotesMcp } from './day-notes.mcp';
 import { PermissionsModule } from '../permissions/permissions.module';
 import { QueryHelpersModule } from '../query-helpers/query-helpers.module';
 import { PlacesModule } from '../places/places.module';
 import { AuthModule } from '../auth/auth.module';
 
 /**
- * Days + day-notes domain (S6 — Phase 2 trip sub-domain). The single prefix
- * /api/trips/:tripId/days covers both the days mount and the nested
- * /days/:dayId/notes mount. DaysMcp/DayNotesMcp carry the
- * decorator-registered MCP tools + resources. DaysService and DayNotesService
- * are exported for in-container consumers (DaysRpc, DayNotesRpc,
- * AccommodationsService, TripsService, the assignments/reservations MCP
- * controllers).
+ * Days (S6 — Phase 2 trip sub-domain), mounted at /api/trips/:tripId/days.
+ * DaysMcp carries the decorator-registered MCP tools + resources. DaysService is
+ * exported for in-container consumers (DaysRpc, AccommodationsService,
+ * TripsService, the assignments/reservations MCP controllers).
+ *
+ * Day notes used to live here too, with their own full file set; they are their
+ * own domain now (day-notes/).
  */
 @Module({
   imports: [PermissionsModule, QueryHelpersModule, PlacesModule, AuthModule, RealtimeModule, PluginGuardsModule],
-  controllers: [DaysController, DayNotesController],
-  providers: [DaysService, DaysMcp, DayNotesService, DayNotesMcp, DayNotesRpc, DaysRpc, AccommodationsRpc],
-  exports: [DaysService, DayNotesService],
+  controllers: [DaysController],
+  providers: [DaysService, DaysMcp, DaysRpc, AccommodationsRpc],
+  exports: [DaysService],
 })
 export class DaysModule {}
diff --git a/server/src/nest/plugins/plugins-runtime.module.ts b/server/src/nest/plugins/plugins-runtime.module.ts
index 80324bb12..94c6c0da3 100644
--- a/server/src/nest/plugins/plugins-runtime.module.ts
+++ b/server/src/nest/plugins/plugins-runtime.module.ts
@@ -20,6 +20,7 @@ import { ReservationsModule } from '../reservations/reservations.module';
 import { TodoModule } from '../todo/todo.module';
 import { PackingModule } from '../packing/packing.module';
 import { DaysModule } from '../days/days.module';
+import { DayNotesModule } from '../day-notes/day-notes.module';
 import { AssignmentsModule } from '../assignments/assignments.module';
 import { LlmParseModule } from '../llm-parse/llm-parse.module';
 import { FilesModule } from '../files/files.module';
@@ -61,7 +62,7 @@ import { JourneyDomainModule } from '../journey/journey-domain.module';
     PluginGuardsModule,
     PluginOAuthModule,
     WeatherModule, TagsModule, CategoriesModule, BudgetModule, ReservationsModule,
-    TodoModule, PackingModule, DaysModule, AssignmentsModule, LlmParseModule,
+    TodoModule, PackingModule, DaysModule, DayNotesModule, AssignmentsModule, LlmParseModule,
     FilesModule, CollabModule, VacayModule, TripsModule, PlacesModule,
     PermissionsModule, AuditModule, AddonsModule, CollectionsModule, AtlasModule,
     NotificationsModule, TripMembershipModule, JourneyDomainModule,
diff --git a/server/tests/e2e/days.e2e.test.ts b/server/tests/e2e/days.e2e.test.ts
index e625c5802..4c1bf5934 100644
--- a/server/tests/e2e/days.e2e.test.ts
+++ b/server/tests/e2e/days.e2e.test.ts
@@ -81,6 +81,10 @@ import { PermissionsService } from '../../src/nest/permissions/permissions.servi
 let checkPermission: MockInstance;
 
 import { DaysModule } from '../../src/nest/days/days.module';
+// The note routes nest under the days prefix but live in their own domain now;
+// this container has to assemble both or /days/:dayId/notes 404s here while
+// working in production.
+import { DayNotesModule } from '../../src/nest/day-notes/day-notes.module';
 import { TrekExceptionFilter } from '../../src/nest/common/trek-exception.filter';
 import { ZodValidationPipe } from '../../src/nest/common/zod-validation.pipe';
 
@@ -89,7 +93,7 @@ describe('Days + day-notes e2e (real auth guard + temp SQLite, real day SQL)', (
   let app: Awaited<ReturnType<typeof build>>;
 
   async function build() {
-    const moduleRef = await Test.createTestingModule({ imports: [DatabaseModule, RealtimeModule, DaysModule] }).compile();
+    const moduleRef = await Test.createTestingModule({ imports: [DatabaseModule, RealtimeModule, DaysModule, DayNotesModule] }).compile();
     const nest = moduleRef.createNestApplication();
     nest.use(cookieParser());
     nest.useGlobalPipes(new ZodValidationPipe());
diff --git a/server/tests/helpers/mcp-test-controllers.ts b/server/tests/helpers/mcp-test-controllers.ts
index 9db4b6a53..4210d521a 100644
--- a/server/tests/helpers/mcp-test-controllers.ts
+++ b/server/tests/helpers/mcp-test-controllers.ts
@@ -16,8 +16,8 @@ import { CollabService } from '../../src/nest/collab/collab.service';
 import { CollectionsMcp } from '../../src/nest/collections/collections.mcp';
 import { CollectionsService } from '../../src/nest/collections/collections.service';
 import { DatabaseService } from '../../src/nest/database/database.service';
-import { DayNotesMcp } from '../../src/nest/days/day-notes.mcp';
-import { DayNotesService } from '../../src/nest/days/day-notes.service';
+import { DayNotesMcp } from '../../src/nest/day-notes/day-notes.mcp';
+import { DayNotesService } from '../../src/nest/day-notes/day-notes.service';
 import { DaysMcp } from '../../src/nest/days/days.mcp';
 import { DaysService } from '../../src/nest/days/days.service';
 import { MapsMcp } from '../../src/nest/maps/maps.mcp';
diff --git a/server/tests/helpers/plugin-host.ts b/server/tests/helpers/plugin-host.ts
index 5548b123f..52f7e6d27 100644
--- a/server/tests/helpers/plugin-host.ts
+++ b/server/tests/helpers/plugin-host.ts
@@ -18,7 +18,7 @@ import { TagsService } from '../../src/nest/tags/tags.service';
 import { CategoriesService } from '../../src/nest/categories/categories.service';
 import { TodoService } from '../../src/nest/todo/todo.service';
 import { PackingService } from '../../src/nest/packing/packing.service';
-import { DayNotesService } from '../../src/nest/days/day-notes.service';
+import { DayNotesService } from '../../src/nest/day-notes/day-notes.service';
 import { DaysService } from '../../src/nest/days/days.service';
 import { AssignmentsService } from '../../src/nest/assignments/assignments.service';
 import { LlmConfigResolver } from '../../src/nest/llm-parse/llm-config.resolver';
@@ -44,7 +44,7 @@ import { WeatherRpc } from '../../src/nest/weather/weather.rpc';
 import { WeatherService } from '../../src/nest/weather/weather.service';
 import { ExchangeRatesRpc } from '../../src/nest/budget/exchange-rates.rpc';
 import { TodoRpc } from '../../src/nest/todo/todo.rpc';
-import { DayNotesRpc } from '../../src/nest/days/day-notes.rpc';
+import { DayNotesRpc } from '../../src/nest/day-notes/day-notes.rpc';
 import { PackingRpc } from '../../src/nest/packing/packing.rpc';
 import { FilesRpc } from '../../src/nest/files/files.rpc';
 import { PlacesRpc } from '../../src/nest/places/places.rpc';
diff --git a/server/tests/helpers/rpc-host-deps.ts b/server/tests/helpers/rpc-host-deps.ts
index b18d5379e..6eb109451 100644
--- a/server/tests/helpers/rpc-host-deps.ts
+++ b/server/tests/helpers/rpc-host-deps.ts
@@ -5,7 +5,7 @@ import { CategoriesRpc } from '../../src/nest/categories/categories.rpc';
 import { WeatherRpc } from '../../src/nest/weather/weather.rpc';
 import { ExchangeRatesRpc } from '../../src/nest/budget/exchange-rates.rpc';
 import { TodoRpc } from '../../src/nest/todo/todo.rpc';
-import { DayNotesRpc } from '../../src/nest/days/day-notes.rpc';
+import { DayNotesRpc } from '../../src/nest/day-notes/day-notes.rpc';
 import { PackingRpc } from '../../src/nest/packing/packing.rpc';
 import { FilesRpc } from '../../src/nest/files/files.rpc';
 import { PlacesRpc } from '../../src/nest/places/places.rpc';
diff --git a/server/tests/unit/days/day-notes.rpc.test.ts b/server/tests/unit/days/day-notes.rpc.test.ts
index 50d8bec24..2e1994f64 100644
--- a/server/tests/unit/days/day-notes.rpc.test.ts
+++ b/server/tests/unit/days/day-notes.rpc.test.ts
@@ -9,9 +9,9 @@ import { expectRegisteredProvider } from '../../helpers/module-providers';
 import { PluginRpcHost } from '../../../src/nest/plugins/host/rpc-host';
 import { createTestPluginRegistry } from '../../../src/nest/plugins/host/rpc-kit/testing';
 import { PluginGuards } from '../../../src/nest/plugins/host/plugin-guards.service';
-import { DayNotesRpc } from '../../../src/nest/days/day-notes.rpc';
-import { DaysModule } from '../../../src/nest/days/days.module';
-import type { DayNotesService } from '../../../src/nest/days/day-notes.service';
+import { DayNotesRpc } from '../../../src/nest/day-notes/day-notes.rpc';
+import { DayNotesModule } from '../../../src/nest/day-notes/day-notes.module';
+import type { DayNotesService } from '../../../src/nest/day-notes/day-notes.service';
 import type { RealtimeService } from '../../../src/nest/realtime/realtime.service';
 import type { DatabaseService } from '../../../src/nest/database/database.service';
 import type { PermissionsService } from '../../../src/nest/permissions/permissions.service';
@@ -115,6 +115,6 @@ describe('DayNotesRpc through the router', () => {
   });
 
   it('DAYNOTES-RPC-009 the class is listed in its module providers', () => {
-    expectRegisteredProvider(DaysModule, DayNotesRpc);
+    expectRegisteredProvider(DayNotesModule, DayNotesRpc);
   });
 });
diff --git a/server/tests/unit/nest/day-notes.service.test.ts b/server/tests/unit/nest/day-notes.service.test.ts
index 334ede046..356f096fa 100644
--- a/server/tests/unit/nest/day-notes.service.test.ts
+++ b/server/tests/unit/nest/day-notes.service.test.ts
@@ -48,7 +48,7 @@ import { resetTestDb } from '../../helpers/test-db';
 import { createUser, createTrip, createDay, addTripMember } from '../../helpers/factories';
 import { DatabaseService } from '../../../src/nest/database/database.service';
 import { PermissionsService } from '../../../src/nest/permissions/permissions.service';
-import { DayNotesService } from '../../../src/nest/days/day-notes.service';
+import { DayNotesService } from '../../../src/nest/day-notes/day-notes.service';
 import type { DayNote } from '../../../src/types';
 import { RealtimeService } from '../../../src/nest/realtime/realtime.service';
 
diff --git a/server/tests/unit/nest/days.controller.test.ts b/server/tests/unit/nest/days.controller.test.ts
index e9407157a..5b88a3c01 100644
--- a/server/tests/unit/nest/days.controller.test.ts
+++ b/server/tests/unit/nest/days.controller.test.ts
@@ -1,11 +1,11 @@
 import { describe, it, expect, vi } from 'vitest';
 import { HttpException } from '@nestjs/common';
 import { DaysController } from '../../../src/nest/days/days.controller';
-import { DayNotesController } from '../../../src/nest/days/day-notes.controller';
-import { DayNoteCreateDto, DayNoteUpdateDto } from '../../../src/nest/days/day-notes.dto';
+import { DayNotesController } from '../../../src/nest/day-notes/day-notes.controller';
+import { DayNoteCreateDto, DayNoteUpdateDto } from '../../../src/nest/day-notes/day-notes.dto';
 import { DayReorderError } from '../../../src/nest/days/days.service';
 import type { DaysService } from '../../../src/nest/days/days.service';
-import type { DayNotesService } from '../../../src/nest/days/day-notes.service';
+import type { DayNotesService } from '../../../src/nest/day-notes/day-notes.service';
 import type { User } from '../../../src/types';
 
 const user = { id: 1, role: 'user', email: 'u@example.test' } as User;
diff --git a/server/tests/unit/plugins/rpc-fallbacks.test.ts b/server/tests/unit/plugins/rpc-fallbacks.test.ts
index e04165965..59954674d 100644
--- a/server/tests/unit/plugins/rpc-fallbacks.test.ts
+++ b/server/tests/unit/plugins/rpc-fallbacks.test.ts
@@ -13,7 +13,7 @@ import { PluginRpcHost } from '../../../src/nest/plugins/host/rpc-host';
 import { createTestPluginRegistry } from '../../../src/nest/plugins/host/rpc-kit/testing';
 import { PluginGuards } from '../../../src/nest/plugins/host/plugin-guards.service';
 import { TagsRpc } from '../../../src/nest/tags/tags.rpc';
-import { DayNotesRpc } from '../../../src/nest/days/day-notes.rpc';
+import { DayNotesRpc } from '../../../src/nest/day-notes/day-notes.rpc';
 import { PlacesRpc } from '../../../src/nest/places/places.rpc';
 import { PackingRpc } from '../../../src/nest/packing/packing.rpc';
 import { FilesRpc } from '../../../src/nest/files/files.rpc';
diff --git a/server/vitest.config.ts b/server/vitest.config.ts
index cc4068213..133d5eef0 100644
--- a/server/vitest.config.ts
+++ b/server/vitest.config.ts
@@ -79,6 +79,7 @@ export default defineConfig({
         'src/nest/common/**/*.ts': { statements: 95, branches: 89, functions: 99, lines: 97 },
         'src/nest/config/**/*.ts': { statements: 99, branches: 100, functions: 99, lines: 99 },
         'src/nest/database/**/*.ts': { statements: 99, branches: 100, functions: 99, lines: 99 },
+        'src/nest/day-notes/**/*.ts': { statements: 92, branches: 82, functions: 98, lines: 97 },
         'src/nest/days/**/*.ts': { statements: 92, branches: 82, functions: 98, lines: 97 },
         'src/nest/feeds/**/*.ts': { statements: 91, branches: 83, functions: 83, lines: 91 },
         'src/nest/files/**/*.ts': { statements: 97, branches: 95, functions: 99, lines: 98 },