diff --git a/CHANGES.md b/CHANGES.md
index 9db8076e..dd8cbd6e 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -3,6 +3,7 @@
 * Update Beautiful Soup 4.6.0 (r449) to 4.6.3 (r475)
 * Update CacheControl library 0.12.4 (bd94f7e) to 0.12.5 (cd91309)
 * Update Certifi 2018.01.18 (e225253) to 2018.08.24 (8be9f89)
+* Update dateutil module 2.7.2 (ff03c0f) to 2.7.2 (49690ee)
 
 
 [develop changelog]
diff --git a/sickbeard/network_timezones.py b/sickbeard/network_timezones.py
index a3043c5c..8df65bf7 100644
--- a/sickbeard/network_timezones.py
+++ b/sickbeard/network_timezones.py
@@ -181,7 +181,7 @@ def _update_zoneinfo():
             # remove the old zoneinfo file
             if cur_zoneinfo is not None:
                 old_file = helpers.real_path(
-                    ek.ek(join, sickbeard.ZONEINFO_DIR, cur_zoneinfo))
+                    ek.ek(os.path.join, sickbeard.ZONEINFO_DIR, cur_zoneinfo))
                 if ek.ek(os.path.exists, old_file):
                     ek.ek(os.remove, old_file)
             # rename downloaded file
@@ -190,6 +190,11 @@ def _update_zoneinfo():
             if '_CLASS_ZONE_INSTANCE' in gettz.func_globals:
                 gettz.func_globals.__setitem__('_CLASS_ZONE_INSTANCE', list())
             tz.gettz.cache_clear()
+            from dateutil.zoneinfo import get_zonefile_instance
+            try:
+                delattr(get_zonefile_instance, '_cached_instance')
+            except AttributeError:
+                pass
 
             sb_timezone = get_tz()
         except:
diff --git a/tests/network_timezone_tests.py b/tests/network_timezone_tests.py
new file mode 100644
index 00000000..22c7a09a
--- /dev/null
+++ b/tests/network_timezone_tests.py
@@ -0,0 +1,51 @@
+import unittest
+import test_lib as test
+import os.path
+import datetime
+from lib.dateutil import tz
+import sickbeard
+from sickbeard import network_timezones, helpers
+import sickbeard.encodingKludge as ek
+
+
+class NetworkTimezoneTests(test.SickbeardTestDBCase):
+    @classmethod
+    def tearDownClass(cls):
+        super(NetworkTimezoneTests, cls).tearDownClass()
+        cls.remove_zoneinfo()
+        try:
+            os.rmdir(sickbeard.ZONEINFO_DIR)
+        except (StandardError, Exception):
+            pass
+
+    @classmethod
+    def setUpClass(cls):
+        super(NetworkTimezoneTests, cls).setUpClass()
+        cls.remove_zoneinfo()
+
+    @classmethod
+    def remove_zoneinfo(cls):
+        # delete all existing zoneinfo files
+        for (path, dirs, files) in ek.ek(os.walk, helpers.real_path(sickbeard.ZONEINFO_DIR)):
+            for filename in files:
+                if filename.endswith('.tar.gz'):
+                    file_w_path = ek.ek(os.path.join, path, filename)
+                    try:
+                        ek.ek(os.remove, file_w_path)
+                    except (StandardError, Exception):
+                        pass
+
+    def test_timezone(self):
+        network_timezones.update_network_dict()
+        network_timezones.sb_timezone = tz.gettz('CET', zoneinfo_priority=True)
+        d = datetime.date(2018, 9, 2).toordinal()
+        t = 'Monday 9:00 PM'
+        network = 'NBC'
+        r = network_timezones.parse_date_time(d, t, network)
+        local_date = datetime.datetime(2018, 9, 3, 3, 0, 0).replace(tzinfo=tz.gettz('CET', zoneinfo_priority=True))
+        self.assertEqual(r, local_date)
+
+
+if __name__ == '__main__':
+    suite = unittest.TestLoader().loadTestsFromTestCase(NetworkTimezoneTests)
+    unittest.TextTestRunner(verbosity=2).run(suite)
diff --git a/tests/test_lib.py b/tests/test_lib.py
index 9ecdb57b..e1eca26b 100644
--- a/tests/test_lib.py
+++ b/tests/test_lib.py
@@ -96,6 +96,7 @@ createTestLogFolder()
 sickbeard.logger.sb_log_instance.init_logging(False)
 
 sickbeard.CACHE_DIR = os.path.join(TESTDIR, 'cache')
+sickbeard.ZONEINFO_DIR = os.path.join(TESTDIR, 'zoneinfo')
 createTestCacheFolder()
 
 #=================