diff --git a/gschliefgraben_glasfaser/main.py b/gschliefgraben_glasfaser/main.py
index 3689b72..6fe0ec9 100644
--- a/gschliefgraben_glasfaser/main.py
+++ b/gschliefgraben_glasfaser/main.py
@@ -9,33 +9,29 @@ import os
 import uuid
 from typing import List
 from itertools import chain
+import json
 # import sys, inspect
 # currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
 # parentdir = os.path.dirname(currentdir)
 # sys.path.insert(0, parentdir)
 # import requests
 from sqlalchemy.orm import session
-from sqlalchemy import func
+from sqlalchemy import func, asc, desc
 # from db.pg_models import Platform
 from gschliefgraben_glasfaser.models import ObservationSchema, Person, PersonSchema, Observation, create_pg_session, Dataset, Procedure, Phenomenon, Platform
 from gschliefgraben_glasfaser.my_api import MyApi
 from datetime import datetime, date, timedelta
-# from db.pg_models import create_pg_session
-#from models import Person, PersonSchema
-# response = requests.get('https://api.com/')
-# print(response)  # shows the response's HTTP status code
-# print(response.json())  # shows the response's JSON response body, if it has one
-# print(response.content)  # get the data content of the response
 
 def main():
     ''' main method '''
     pg_session: session = create_pg_session()
     platform_sta_identifier = "gschliefgraben_glasfaser"  
     # sensor_list = ["inclino1_14", "inclino1_02"]
-    sensor_list = os.environ.get("GLASFASER_GSCHLIEFGRABEN_SENSORS")
+    #sensor_list = os.environ.get("GLASFASER_GSCHLIEFGRABEN_SENSORS")
+    sensor_list = json.loads(os.environ['GLASFASER_GSCHLIEFGRABEN_SENSORS'])
     
     # this will print elements along with their index value
-    for sensor in enumerate(sensor_list):
+    for sensor in sensor_list:
     
         pg_query = pg_session.query(Dataset) \
             .join(Procedure) \
@@ -66,6 +62,27 @@ def main():
             
         # create all the observation for the given sensor names
         create_observations(sensor, slope_dataset)
+        
+        # update first and last observations for the dataset
+        first_slope_observation = pg_session.query(Observation) \
+            .filter(Observation.fk_dataset_id == slope_dataset.id) \
+            .order_by(asc('sampling_time_start')) \
+            .first()
+        if first_slope_observation is not None:
+            slope_dataset.first_time = first_slope_observation.sampling_time_start
+            slope_dataset.first_value = first_slope_observation.value_quantity
+            slope_dataset.fk_first_observation_id = first_slope_observation.id
+        last_slope_observation = pg_session.query(Observation) \
+            .filter(Observation.fk_dataset_id == slope_dataset.id) \
+            .order_by(desc('sampling_time_start')) \
+            .first()
+        if last_slope_observation is not None:
+            slope_dataset.last_time = last_slope_observation.sampling_time_start
+            slope_dataset.last_value = last_slope_observation.value_quantity
+            slope_dataset.fk_last_observation_id = last_slope_observation.id
+            
+        pg_session.commit()
+        pg_session.close()
     
 def create_observations(sensor: str, slope_dataset: Dataset):
     ''' create_observations method for given sensor '''    
diff --git a/gschliefgraben_glasfaser/update_daily_cron.py b/gschliefgraben_glasfaser/update_daily_cron.py
index 77d2fed..381ec33 100644
--- a/gschliefgraben_glasfaser/update_daily_cron.py
+++ b/gschliefgraben_glasfaser/update_daily_cron.py
@@ -5,10 +5,10 @@ Sqlalchemy version: 1.2.15
 Python version: 3.10
 '''
 
-import os
+import os, json
 import uuid
 from sqlalchemy.orm import session
-from sqlalchemy import func
+from sqlalchemy import func, asc, desc
 # from db.pg_models import Platform
 from gschliefgraben_glasfaser.models import ObservationSchema, Observation, create_pg_session, Dataset, Procedure, Phenomenon, Platform
 from gschliefgraben_glasfaser.my_api import MyApi
@@ -19,10 +19,11 @@ def main():
     pg_session: session = create_pg_session()
     platform_sta_identifier = "gschliefgraben_glasfaser"  
     # sensor_list = ["inclino1_14", "inclino1_02"]
-    sensor_list = os.environ.get("GLASFASER_GSCHLIEFGRABEN_SENSORS")
-     
+    #sensor_list = os.environ.get("GLASFASER_GSCHLIEFGRABEN_SENSORS")
+    sensor_list = json.loads(os.environ['GLASFASER_GSCHLIEFGRABEN_SENSORS'])
+    
     # this will print elements along with their index value
-    for sensor in enumerate(sensor_list):
+    for sensor in sensor_list:
         pg_query = pg_session.query(Dataset) \
             .join(Procedure) \
             .join(Phenomenon) \
@@ -50,6 +51,27 @@ def main():
             
         # create all the observation for the given sensor names
         create_observations(sensor, slope_dataset)
+        
+        first_slope_observation = pg_session.query(Observation) \
+            .filter(Observation.fk_dataset_id == slope_dataset.id) \
+            .order_by(asc('sampling_time_start')) \
+            .first()
+        if first_slope_observation is not None:
+            slope_dataset.first_time = first_slope_observation.sampling_time_start
+            slope_dataset.first_value = first_slope_observation.value_quantity
+            slope_dataset.fk_first_observation_id = first_slope_observation.id
+        last_slope_observation = pg_session.query(Observation) \
+            .filter(Observation.fk_dataset_id == slope_dataset.id) \
+            .order_by(desc('sampling_time_start')) \
+            .first()
+        if last_slope_observation is not None:
+            slope_dataset.last_time = last_slope_observation.sampling_time_start
+            slope_dataset.last_value = last_slope_observation.value_quantity
+            slope_dataset.fk_last_observation_id = last_slope_observation.id
+            
+        pg_session.commit()
+        pg_session.close()
+
     
 def create_observations(sensor: str, slope_dataset: Dataset):
     ''' create_observations method for given sensor '''