diff --git a/generate_ical.py b/generate_ical.py
index 8f4372f..a597673 100644
--- a/generate_ical.py
+++ b/generate_ical.py
@@ -3,6 +3,8 @@ import icalendar
 import datetime
 import requests
 import urllib
+import glob
+import pytz
 import json
 import os
 
@@ -77,15 +79,16 @@ for trash_type in trash_types:
   if not os.path.exists(trash_type_folder):
     os.makedirs(trash_type_folder)
 
-  for f in next(os.walk(trash_type_folder), (None, None, []))[2]:
+  for f in os.listdir(trash_type_folder):
     ical_path = os.path.join(trash_type_folder, f)
-    with open(ical_path, "rb") as fh:
-      try:
-        cal = icalendar.Calendar.from_ical(fh.read())
-      except ValueError:
-        print("{} is not an parsable ical file".format(ical_path))
-        continue
-      if cal.walk()[1]["DTSTAMP"].dt.year == current_year:
+    if os.path.isfile(ical_path):
+      with open(ical_path, "rb") as fh:
+        try:
+          cal = icalendar.Calendar.from_ical(fh.read())
+        except ValueError:
+          print("{} is not an parsable ical file".format(ical_path))
+          continue
+      if cal.walk()[1]["DTSTART"].dt > datetime.datetime.now(pytz.utc):
         os.remove(ical_path)
 
   radicale_prop_file = os.path.join(trash_type_folder, ".Radicale.props")