diff --git a/selfprivacy_api/migrations/add_monitoring.py b/selfprivacy_api/migrations/add_monitoring.py
index 965e234..82f7b64 100644
--- a/selfprivacy_api/migrations/add_monitoring.py
+++ b/selfprivacy_api/migrations/add_monitoring.py
@@ -33,5 +33,5 @@ class AddMonitoring(Migration):
             if "monitoring" not in data["modules"]:
                 data["modules"]["monitoring"] = {
                     "enable": True,
-                    "location": BlockDevices().get_root_block_device().name
+                    "location": BlockDevices().get_root_block_device().name,
                 }
diff --git a/selfprivacy_api/services/prometheus/__init__.py b/selfprivacy_api/services/prometheus/__init__.py
index a7516f5..028709a 100644
--- a/selfprivacy_api/services/prometheus/__init__.py
+++ b/selfprivacy_api/services/prometheus/__init__.py
@@ -12,7 +12,7 @@ from selfprivacy_api.services.prometheus.icon import PROMETHEUS_ICON
 
 
 class Prometheus(Service):
-    """Class representing Pleroma service."""
+    """Class representing Prometheus service."""
 
     @staticmethod
     def get_id() -> str:
@@ -24,7 +24,7 @@ class Prometheus(Service):
 
     @staticmethod
     def get_description() -> str:
-        return "Prometheus is a free software application used for event monitoring and alerting."
+        return "Prometheus is used for resource monitoring and alerts."
 
     @staticmethod
     def get_svg_icon() -> str:
@@ -49,7 +49,7 @@ class Prometheus(Service):
 
     @staticmethod
     def get_backup_description() -> str:
-        return "For Prometheus backups are not available."
+        return "Backups are not available for Prometheus."
 
     @staticmethod
     def get_status() -> ServiceStatus:
diff --git a/selfprivacy_api/utils/prometheus.py b/selfprivacy_api/utils/prometheus.py
index 5547497..60f12aa 100644
--- a/selfprivacy_api/utils/prometheus.py
+++ b/selfprivacy_api/utils/prometheus.py
@@ -44,81 +44,105 @@ class PrometheusQueries:
 
     @staticmethod
     def cpu_usage(
-        start: Optional[int] = None,
-        end: Optional[int] = None,
+        start: Optional[datetime] = None,
+        end: Optional[datetime] = None,
         step: int = 60,  # seconds
     ) -> PrometheusQueryResult:
         """
         Get CPU information.
 
         Args:
-            start (int, optional): Unix timestamp indicating the start time.
+            start (datetime, optional): The start time.
                 Defaults to 20 minutes ago if not provided.
-            end (int, optional): Unix timestamp indicating the end time.
+            end (datetime, optional): The end time.
                 Defaults to current time if not provided.
             step (int): Interval in seconds for querying disk usage data.
         """
 
-        if not start:
-            start = int((datetime.now() - timedelta(minutes=20)).timestamp())
+        if start is None:
+            start = datetime.now() - timedelta(minutes=20)
 
-        if not end:
-            end = int(datetime.now().timestamp())
+        if end is None:
+            end = datetime.now()
+
+        start_timestamp = int(start.timestamp())
+        end_timestamp = int(end.timestamp())
 
         query = '100 - (avg by (instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)'
 
-        return PrometheusQueries._send_query(query, start, end, step)
+        return PrometheusQueries._send_query(
+            query,
+            start_timestamp,
+            end_timestamp,
+            step,
+        )
 
     @staticmethod
     def memory_usage(
-        start: Optional[int] = None,
-        end: Optional[int] = None,
+        start: Optional[datetime] = None,
+        end: Optional[datetime] = None,
         step: int = 60,  # seconds
     ) -> PrometheusQueryResult:
         """
         Get memory usage.
 
         Args:
-            start (int, optional): Unix timestamp indicating the start time.
+            start (datetime, optional): The start time.
                 Defaults to 20 minutes ago if not provided.
-            end (int, optional): Unix timestamp indicating the end time.
+            end (datetime, optional): The end time.
                 Defaults to current time if not provided.
             step (int): Interval in seconds for querying memory usage data.
         """
 
-        if not start:
-            start = int((datetime.now() - timedelta(minutes=20)).timestamp())
+        if start is None:
+            start = datetime.now() - timedelta(minutes=20)
 
-        if not end:
-            end = int(datetime.now().timestamp())
+        if end is None:
+            end = datetime.now()
+
+        start_timestamp = int(start.timestamp())
+        end_timestamp = int(end.timestamp())
 
         query = "100 - (100 * (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes))"
 
-        return PrometheusQueries._send_query(query, start, end, step)
+        return PrometheusQueries._send_query(
+            query,
+            start_timestamp,
+            end_timestamp,
+            step,
+        )
 
     @staticmethod
     def disk_usage(
-        start: Optional[int] = None,
-        end: Optional[int] = None,
+        start: Optional[datetime] = None,
+        end: Optional[datetime] = None,
         step: int = 60,  # seconds
     ) -> PrometheusQueryResult:
         """
         Get disk usage information.
 
         Args:
-            start (int, optional): Unix timestamp indicating the start time.
+            start (datetime, optional): The start time.
                 Defaults to 20 minutes ago if not provided.
-            end (int, optional): Unix timestamp indicating the end time.
+            end (datetime, optional): The end time.
                 Defaults to current time if not provided.
             step (int): Interval in seconds for querying disk usage data.
         """
 
-        if not start:
-            start = int((datetime.now() - timedelta(minutes=20)).timestamp())
+        if start is None:
+            start = datetime.now() - timedelta(minutes=20)
 
-        if not end:
-            end = int(datetime.now().timestamp())
+        if end is None:
+            end = datetime.now()
+
+        start_timestamp = int(start.timestamp())
+        end_timestamp = int(end.timestamp())
 
         query = """100 - (100 * sum by (device) (node_filesystem_avail_bytes{fstype!="rootfs"}) / sum by (device) (node_filesystem_size_bytes{fstype!="rootfs"}))"""
 
-        return PrometheusQueries._send_query(query, start, end, step)
+        return PrometheusQueries._send_query(
+            query,
+            start_timestamp,
+            end_timestamp,
+            step,
+        )