diff --git a/apiserver/bll/project/project_bll.py b/apiserver/bll/project/project_bll.py
index 2a6036c..95a8661 100644
--- a/apiserver/bll/project/project_bll.py
+++ b/apiserver/bll/project/project_bll.py
@@ -40,7 +40,8 @@ from .sub_projects import (
     _ids_with_children,
     _ids_with_parents,
     _get_project_depth,
-    ProjectsChildren, _get_writable_project_from_name,
+    ProjectsChildren,
+    _get_writable_project_from_name,
 )
 
 log = config.logger(__file__)
diff --git a/apiserver/bll/serving/__init__.py b/apiserver/bll/serving/__init__.py
index 9d815b6..a8e80b2 100644
--- a/apiserver/bll/serving/__init__.py
+++ b/apiserver/bll/serving/__init__.py
@@ -1,4 +1,4 @@
-from datetime import datetime, timedelta
+from datetime import datetime, timedelta, timezone
 from enum import Enum, auto
 from operator import attrgetter
 from time import time
@@ -75,7 +75,7 @@ class ServingBLL:
         """
         Register a serving container
         """
-        now = datetime.utcnow()
+        now = datetime.now(timezone.utc)
         key = self._get_container_key(company_id, request.container_id)
         entry = ServingContainerEntry(
             **request.to_struct(),
@@ -120,7 +120,7 @@ class ServingBLL:
         Serving container status report
         """
         container_id = report.container_id
-        now = datetime.utcnow()
+        now = datetime.now(timezone.utc)
         entry = self._get_serving_container_entry(company_id, container_id)
         if entry:
             ip = ip or entry.ip
@@ -252,7 +252,7 @@ class ServingBLL:
             "instances": len(entries),
             **{counter.name: counter() for counter in counters},
         }
-        ret["last_update"] = self._naive_time(ret.get("last_update"))
+        ret["last_update"] = ret.get("last_update")
         return ret
 
     def get_endpoints(self, company_id: str):
@@ -307,18 +307,12 @@ class ServingBLL:
                 "input_type": entry.input_type,
                 "input_size": entry.input_size,
                 "uptime_sec": entry.uptime_sec,
-                "last_update": self._naive_time(entry.last_activity_time),
+                "age_sec": int((datetime.now(timezone.utc) - entry.register_time).total_seconds()),
+                "last_update": entry.last_activity_time,
             }
             for entry in entries
         ]
 
-    @staticmethod
-    def _naive_time(input_: datetime) -> datetime:
-        if not isinstance(input_, datetime):
-            return input_
-
-        return input_.replace(tzinfo=None)
-
     def get_endpoint_details(self, company_id, endpoint_url: str) -> dict:
         entries = self._get_endpoint_entries(company_id, endpoint_url)
         if not entries:
@@ -346,7 +340,7 @@ class ServingBLL:
             "model_source": first_entry.model_source,
             "model_version": first_entry.model_version,
             "uptime_sec": max(e.uptime_sec for e in entries),
-            "last_update": self._naive_time(max(e.last_activity_time for e in entries)),
+            "last_update": max(e.last_activity_time for e in entries),
             "instances": [
                 {
                     "id": entry.container_id,
@@ -354,7 +348,7 @@ class ServingBLL:
                     "requests": entry.requests_num,
                     "requests_min": entry.requests_min,
                     "latency_ms": entry.latency_ms,
-                    "last_update": self._naive_time(entry.last_activity_time),
+                    "last_update": entry.last_activity_time,
                     "reference": [ref.to_struct() for ref in entry.reference]
                     if isinstance(entry.reference, list)
                     else entry.reference,
diff --git a/apiserver/bll/serving/stats.py b/apiserver/bll/serving/stats.py
index 47aba59..6238151 100644
--- a/apiserver/bll/serving/stats.py
+++ b/apiserver/bll/serving/stats.py
@@ -1,5 +1,5 @@
 from collections import defaultdict
-from datetime import datetime
+from datetime import datetime, timezone
 from enum import Enum
 
 from typing import Tuple, Optional, Sequence
@@ -35,7 +35,7 @@ class ServingStats:
     @staticmethod
     def _get_es_index_suffix():
         """Get the index name suffix for storing current month data"""
-        return datetime.utcnow().strftime("%Y-%m")
+        return datetime.now(timezone.utc).strftime("%Y-%m")
 
     @staticmethod
     def _get_average_value(value) -> Tuple[Optional[float], Optional[int]]:
@@ -292,7 +292,7 @@ class ServingStats:
         hist_ret["total"]["values"] = cls.round_series(total)
         hist_ret["instances"] = {
             key: {"title": key, "dates": dates_, "values": cls.round_series(values)}
-            for key, values in instances.items()
+            for key, values in sorted(instances.items(), key=lambda p: p[0])
         }
 
         return hist_ret
diff --git a/apiserver/schema/services/serving.conf b/apiserver/schema/services/serving.conf
index be990a9..86fb68a 100644
--- a/apiserver/schema/services/serving.conf
+++ b/apiserver/schema/services/serving.conf
@@ -190,6 +190,10 @@ _definitions {
                 format: "date-time"
                 description: The latest time when the container instance sent update
             }
+            age_sec {
+                type: integer
+                description: Amount of seconds since the container registration
+            }
         }
     }
     metrics_history_series {