diff --git a/api/advent22_api/routers/_security.py b/api/advent22_api/routers/_security.py
new file mode 100644
index 0000000..aff2ab5
--- /dev/null
+++ b/api/advent22_api/routers/_security.py
@@ -0,0 +1,47 @@
+import secrets
+from datetime import date
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import HTTPBasic, HTTPBasicCredentials
+
+from ..core.config import Config
+
+security = HTTPBasic()
+
+
+async def user_is_admin(
+    credentials: HTTPBasicCredentials = Depends(security),
+    config: Config = Depends(Config.get_config),
+) -> bool:
+    username_correct = secrets.compare_digest(credentials.username, config.admin.name)
+
+    password_correct = secrets.compare_digest(
+        credentials.password, config.admin.password
+    )
+
+    return username_correct and password_correct
+
+
+async def require_admin(
+    is_admin: bool = Depends(user_is_admin),
+) -> None:
+    if not is_admin:
+        raise HTTPException(status.HTTP_401_UNAUTHORIZED)
+
+
+async def user_visible_days() -> int:
+    today = date.today()
+
+    if today.month == 12:
+        return today.day
+
+    if today.month in (1, 2, 3):
+        return 24
+
+    return 0
+
+
+async def user_can_view_day(
+    day: int,
+) -> bool:
+    return day < await user_visible_days()
diff --git a/api/advent22_api/routers/days.py b/api/advent22_api/routers/days.py
index e101317..991d66f 100644
--- a/api/advent22_api/routers/days.py
+++ b/api/advent22_api/routers/days.py
@@ -7,7 +7,7 @@ from PIL import Image
 from ..core.config import Config
 from ..core.depends import get_image, get_part, shuffle_solution
 from ..core.image_helpers import api_return_image
-from .user import user_is_admin
+from ._security import user_can_view_day, user_is_admin, user_visible_days
 
 router = APIRouter(prefix="/days", tags=["days"])
 
@@ -23,30 +23,30 @@ async def startup() -> None:
 
 @router.get("/date")
 async def get_date() -> str:
+    """
+    Aktuelles Server-Datum
+    """
+
     return date.today().isoformat()
 
 
 @router.get("/visible_days")
 async def get_visible_days() -> int:
-    today = date.today()
+    """
+    Sichtbare Türchen
+    """
 
-    if today.month == 12:
-        return today.day
-
-    if today.month in (1, 2, 3):
-        return 24
-
-    return 0
-
-
-async def user_can_view(
-    day: int,
-) -> bool:
-    return day < await get_visible_days()
+    return await user_visible_days()
 
 
 @router.get("/part/{day}")
-async def get_part_for_day(part: str = Depends(get_part)) -> str:
+async def get_part_for_day(
+    part: str = Depends(get_part),
+) -> str:
+    """
+    Heutiger Lösungsteil
+    """
+
     return part
 
 
@@ -56,7 +56,7 @@ async def get_part_for_day(part: str = Depends(get_part)) -> str:
 )
 async def get_image_for_day(
     image: Image.Image = Depends(get_image),
-    can_view: bool = Depends(user_can_view),
+    can_view: bool = Depends(user_can_view_day),
     is_admin: bool = Depends(user_is_admin),
 ) -> StreamingResponse:
     """
diff --git a/api/advent22_api/routers/user.py b/api/advent22_api/routers/user.py
index 255b54b..46fa28b 100644
--- a/api/advent22_api/routers/user.py
+++ b/api/advent22_api/routers/user.py
@@ -1,32 +1,8 @@
-import secrets
+from fastapi import APIRouter, Depends
 
-from fastapi import APIRouter, Depends, HTTPException, status
-from fastapi.security import HTTPBasic, HTTPBasicCredentials
-
-from ..core.config import Config
+from ._security import require_admin
 
 router = APIRouter(prefix="/user", tags=["user"])
-security = HTTPBasic()
-
-
-async def user_is_admin(
-    credentials: HTTPBasicCredentials = Depends(security),
-    config: Config = Depends(Config.get_config),
-) -> bool:
-    username_correct = secrets.compare_digest(credentials.username, config.admin.name)
-
-    password_correct = secrets.compare_digest(
-        credentials.password, config.admin.password
-    )
-
-    return username_correct and password_correct
-
-
-async def require_admin(
-    is_admin: bool = Depends(user_is_admin),
-) -> None:
-    if not is_admin:
-        raise HTTPException(status.HTTP_401_UNAUTHORIZED)
 
 
 @router.get("/admin")