diff --git a/pysqm/plot.py b/pysqm/plot.py
index a106eebb2c46321df94e762a6337a85d22cf296f..1e0041ccc6108bb2aa9919e29221ac918cd934bd 100644
--- a/pysqm/plot.py
+++ b/pysqm/plot.py
@@ -830,7 +830,7 @@ def make_plot(input_filename=None,send_emails=False,write_stats=False):
     output_filenames = [\
         str("%s/%s_%s.png" %(config.current_data_directory,\
             config._device_shorttype,config._observatory_name)),\
-        str("%s/%s_%s-%s.png"\
+        str("%s/%s_%s_%s.png"\
             %(config.daily_graph_directory+str(NSBData.Night)[0:7].replace('-',''),\
               str(NSBData.Night).replace('-',''),config._device_shorttype, config._observatory_name))\
     ]
diff --git a/pysqm/read.py b/pysqm/read.py
index 6724f09a69acdacc933cbdb5fe3227d86bd8a622..71cba3090be359a44f58163e79608123576a95ad 100644
--- a/pysqm/read.py
+++ b/pysqm/read.py
@@ -190,12 +190,11 @@ class device(observatory):
         self.yearmonthday = yearmonthday
 
         self.monthly_datafile = \
-        config.monthly_data_directory+"/"+config._device_shorttype+\
-         "_"+config._observatory_name+"_"+yearmonth+".dat"
+         config.monthly_data_directory+"/"+yearmonth+"_"+\
+         config._device_shorttype+"_"+config._observatory_name+"_"+".dat"
         self.daily_datafile = \
          config.daily_data_directory+"/"+yearmonth+"/"+\
-         "_"+config._device_shorttype+'_'+config._observatory_name+\
-         "_"+yearmonthday+'.dat'
+         yearmonthday+"_"+config._device_shorttype+"_"+config._observatory_name+'.dat'
         self.current_datafile = \
          config.current_data_directory+"/"+config._device_shorttype+\
          "_"+config._observatory_name+".dat"