diff --git a/helper/helper.py b/helper/helper.py
index 9565f84..51fe0e9 100644
--- a/helper/helper.py
+++ b/helper/helper.py
@@ -6,6 +6,7 @@ Copyright © 2020 Project Author Pilar Monsalvete Alvarez de Uribarri pilar.mons
 
 import pandas as pd
 import numpy as np
+import calendar as cal
 import helpers.constants as cte
 
 
@@ -22,16 +23,17 @@ class Helper:
     """
     array = []
     for i in range(0, 12):
-      total_hours = cte.days_of_month[i] * 24
+      days_of_month = cal.monthrange(2015, i+1)
+      total_hours = days_of_month * 24
       array = np.concatenate((array, np.full(total_hours, i + 1)))
-    self._month_hour = pd.DataFrame(array, columns=['month'])
+    self._month_hour = pd.DataFrame(array, columns=cte.MONTH)
     return self._month_hour
 
   def get_mean_values(self, values):
     out = None
     if values is not None:
-      if 'month' not in values.columns:
+      if cte.MONTH not in values.columns:
         values = pd.concat([self.month_hour, pd.DataFrame(values)], axis=1)
-      out = values.groupby('month', as_index=False).mean()
-      del out['month']
+      out = values.groupby(cte.MONTH, as_index=False).mean()
+      del out[cte.MONTH]
     return out
diff --git a/simplified_radiosity_algorithm.py b/simplified_radiosity_algorithm.py
index e5d4f5f..37034e1 100644
--- a/simplified_radiosity_algorithm.py
+++ b/simplified_radiosity_algorithm.py
@@ -14,6 +14,7 @@ from subprocess import SubprocessError, TimeoutExpired, CalledProcessError
 from exports.exports_factory import ExportsFactory
 from imports.weather_factory import WeatherFactory
 from helper.helper import Helper as mv
+import helpers.constants as cte
 
 
 class SimplifiedRadiosityAlgorithm:
@@ -44,11 +45,11 @@ class SimplifiedRadiosityAlgorithm:
     self._results = None
     self._radiation = []
 
-  def call_sra(self, keep_files=False):
+  def call_sra(self, key, keep_files=False):
     """
     creates required input files and calls the software
     """
-    self._create_cli_file()
+    self._create_cli_file(key)
     ExportsFactory('sra', self._city, self._tmp_path).export()
     try:
       completed = subprocess.run([self._executable, str(Path(self._tmp_path / self._sra_in_file_name).resolve())])
@@ -113,28 +114,30 @@ class SimplifiedRadiosityAlgorithm:
 
       building = city.city_object(city_object_name)
       for column in radiation.columns.values:
-        if column == 'month':
+        if column == cte.MONTH:
           continue
         header_id = column
         surface_id = header_id.split(':')[2]
         surface = building.surface_by_id(surface_id)
         new_value = pd.DataFrame(radiation[[header_id]].to_numpy(), columns=['sra'])
         if mode == 0 or mode == 2:
+          # todo: this is wrong?? It must be used like this in MEB or what??
           month_new_value = mv().get_mean_values(new_value)
-          if 'month' not in surface.global_irradiance:
-            surface.global_irradiance['month'] = month_new_value
+          if cte.MONTH not in surface.global_irradiance:
+            surface.global_irradiance[cte.MONTH] = month_new_value
           else:
-            pd.concat([surface.global_irradiance['month'], month_new_value], axis=1)
+            pd.concat([surface.global_irradiance[cte.MONTH], month_new_value], axis=1)
         if mode == 1 or mode == 2:
-          if 'hour' not in surface.global_irradiance:
-            surface.global_irradiance['hour'] = new_value
+          if cte.HOUR not in surface.global_irradiance:
+            surface.global_irradiance[cte.HOUR] = new_value
           else:
-            pd.concat([surface.global_irradiance['hour'], new_value], axis=1)
+            pd.concat([surface.global_irradiance[cte.HOUR], new_value], axis=1)
 
-  def _create_cli_file(self):
+  def _create_cli_file(self, key):
     file = self._city.climate_file
+    print(file)
     days_in_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
-    WeatherFactory('epw', self._city, file_name=self._weather_file_name).enrich()
+    WeatherFactory(key, self._city, file_name=self._weather_file_name).enrich()
     content = self._city.name + '\n'
     content += str(self._city.latitude) + ',' + str(self._city.longitude) + ',0.0,' + str(self._city.time_zone) + '\n'
     content += '\ndm  m h G_Dh  G_Bn\n'
@@ -150,8 +153,8 @@ class SimplifiedRadiosityAlgorithm:
             i = (total_days+day-1)*24 + hour - 1
           representative_building = self._city.buildings[0]
           content += str(day) + '  ' + str(month) + '  ' + str(hour) + '  ' \
-              + str(representative_building.global_horizontal['hour'].epw[i]) + '  ' \
-              + str(representative_building.beam['hour'].epw[i]) + '\n'
+              + str(representative_building.global_horizontal[cte.HOUR].epw[i]) + '  ' \
+              + str(representative_building.beam[cte.HOUR].epw[i]) + '\n'
     with open(file, "w") as file:
       file.write(content)
     return