diff --git a/src/govoplan_core/core/install_config.py b/src/govoplan_core/core/install_config.py
index 7ef7caa..8d51f81 100644
--- a/src/govoplan_core/core/install_config.py
+++ b/src/govoplan_core/core/install_config.py
@@ -340,6 +340,7 @@ CELERY_ENABLED=true
 REDIS_URL=redis://127.0.0.1:6379/0
 CELERY_QUEUES=send_email,append_sent,notifications,calendar,default
 CALENDAR_OUTBOX_TERMINAL_RETENTION_DAYS=90
+SCHEDULING_CANCELLATION_NOTICE_DAYS=30
 
 # Deployment-wide connector egress policy. Enable private networks only when
 # this installation intentionally integrates with internal services.
@@ -405,6 +406,7 @@ REDIS_URL=redis://127.0.0.1:56379/0
 CELERY_ENABLED=true
 CELERY_QUEUES=send_email,append_sent,notifications,calendar,default
 CALENDAR_OUTBOX_TERMINAL_RETENTION_DAYS=90
+SCHEDULING_CANCELLATION_NOTICE_DAYS=30
 
 GOVOPLAN_CONNECTOR_ALLOW_PRIVATE_NETWORKS=true
 GOVOPLAN_CONNECTOR_MAX_STRUCTURED_RESPONSE_BYTES=16777216
diff --git a/src/govoplan_core/settings.py b/src/govoplan_core/settings.py
index a51d881..b77407d 100644
--- a/src/govoplan_core/settings.py
+++ b/src/govoplan_core/settings.py
@@ -76,6 +76,12 @@ class Settings(BaseSettings):
         ge=0,
         alias="CALENDAR_OUTBOX_TERMINAL_RETENTION_DAYS",
     )
+    scheduling_cancellation_notice_days: int = Field(
+        default=30,
+        ge=1,
+        le=90,
+        alias="SCHEDULING_CANCELLATION_NOTICE_DAYS",
+    )
     mock_mailbox_dir: str = Field(default="runtime/mock-mailbox", alias="MOCK_MAILBOX_DIR")
 
     # Development bootstrap only. Do not use this in production.
diff --git a/tests/test_install_config.py b/tests/test_install_config.py
index a351aec..7eca299 100644
--- a/tests/test_install_config.py
+++ b/tests/test_install_config.py
@@ -21,6 +21,18 @@ class InstallConfigTests(unittest.TestCase):
         with self.assertRaises(ValidationError):
             Settings(CALENDAR_OUTBOX_TERMINAL_RETENTION_DAYS="-1")
 
+    def test_scheduling_cancellation_notice_setting_is_bounded(self) -> None:
+        self.assertEqual(Settings().scheduling_cancellation_notice_days, 30)
+        self.assertEqual(
+            Settings(
+                SCHEDULING_CANCELLATION_NOTICE_DAYS="14"
+            ).scheduling_cancellation_notice_days,
+            14,
+        )
+        for invalid in ("0", "91"):
+            with self.subTest(invalid=invalid), self.assertRaises(ValidationError):
+                Settings(SCHEDULING_CANCELLATION_NOTICE_DAYS=invalid)
+
     def test_self_hosted_validation_reports_actionable_missing_settings(self) -> None:
         result = validate_runtime_configuration({}, profile="self-hosted")
 
@@ -113,6 +125,7 @@ class InstallConfigTests(unittest.TestCase):
         self.assertIn("GOVOPLAN_INSTALL_PROFILE=self-hosted", self_hosted)
         self.assertIn("MASTER_KEY_B64=<generate", self_hosted)
         self.assertIn("CALENDAR_OUTBOX_TERMINAL_RETENTION_DAYS=90", self_hosted)
+        self.assertIn("SCHEDULING_CANCELLATION_NOTICE_DAYS=30", self_hosted)
         self.assertIn("GOVOPLAN_CONNECTOR_ALLOW_PRIVATE_NETWORKS=false", self_hosted)
         self.assertIn("GOVOPLAN_CONNECTOR_SECRET_ENV_ALLOWLIST=", self_hosted)
         self.assertIn("GOVOPLAN_CONNECTOR_CA_BUNDLE_ALLOWLIST=", self_hosted)
@@ -122,6 +135,7 @@ class InstallConfigTests(unittest.TestCase):
         self.assertIn("GOVOPLAN_INSTALL_PROFILE=production-like", production_like)
         self.assertNotIn("MASTER_KEY_B64=<generate", production_like)
         self.assertIn("CALENDAR_OUTBOX_TERMINAL_RETENTION_DAYS=90", production_like)
+        self.assertIn("SCHEDULING_CANCELLATION_NOTICE_DAYS=30", production_like)
         self.assertIn("GOVOPLAN_CONNECTOR_ALLOW_PRIVATE_NETWORKS=true", production_like)
         self.assertIn("GOVOPLAN_CONNECTOR_SECRET_ENV_ALLOWLIST=", production_like)
         self.assertIn("GOVOPLAN_CONNECTOR_CA_BUNDLE_ALLOWLIST=", production_like)