diff --git a/rdiffweb/plugins/remove_older/__init__.py b/rdiffweb/plugins/remove_older/__init__.py
index c3ad1fb94a8293c8ea63d4fe147daab3794d2801..dc419fcf5a1de34d70c56158133fe7c1c177feb7 100644
--- a/rdiffweb/plugins/remove_older/__init__.py
+++ b/rdiffweb/plugins/remove_older/__init__.py
@@ -34,9 +34,7 @@ from rdiffweb import rdw_spider_repos, page_main, librdiff
 from rdiffweb.dispatch import poppath
 from rdiffweb.i18n import ugettext as _
 from rdiffweb.page_main import MainPage
-from rdiffweb.rdw_plugin import IPreferencesPanelProvider, ITemplateFilterPlugin, \
-    IDeamonPlugin, JobPlugin
-
+from rdiffweb.rdw_plugin import IPreferencesPanelProvider, ITemplateFilterPlugin, JobPlugin
 
 _logger = logging.getLogger(__name__)
 
diff --git a/rdiffweb/plugins/set_encoding/__init__.py b/rdiffweb/plugins/set_encoding/__init__.py
index 1cf4293122a93362db3a430baaea49ef29f0da24..d992803961b6a5c0dd3141e8830c08e03edeb895 100644
--- a/rdiffweb/plugins/set_encoding/__init__.py
+++ b/rdiffweb/plugins/set_encoding/__init__.py
@@ -35,9 +35,7 @@ from rdiffweb import rdw_spider_repos, page_main, librdiff
 from rdiffweb.dispatch import poppath
 from rdiffweb.i18n import ugettext as _
 from rdiffweb.page_main import MainPage
-from rdiffweb.rdw_plugin import IPreferencesPanelProvider, ITemplateFilterPlugin, \
-    IDeamonPlugin
-
+from rdiffweb.rdw_plugin import IPreferencesPanelProvider, ITemplateFilterPlugin
 
 _logger = logging.getLogger(__name__)
 
diff --git a/rdiffweb/rdw_plugin.py b/rdiffweb/rdw_plugin.py
index ba0bf96e3927a4c1f57b7b4f6aab15332b17e903..b6d24bfe8af8eff76f9a6c475bae04d7201ef1f9 100644
--- a/rdiffweb/rdw_plugin.py
+++ b/rdiffweb/rdw_plugin.py
@@ -31,14 +31,13 @@ import os
 from pkg_resources import working_set, Environment
 import pkg_resources
 import sys
+import time
 
 from rdiffweb.dispatch import static
 
-
 # Define logger for this module
 logger = logging.getLogger(__name__)
 
-
 PluginInfo = namedtuple(
     'PluginInfo',
     ['name', 'version', 'author', 'description', 'path', 'enabled', 'url', 'copyright'])
@@ -430,12 +429,11 @@ class IDeamonPlugin(IRdiffwebPlugin):
     """
     CATEGORY = "Daemon"
 
-    @property
-    def deamon_frequency(self):
-        """
-        Return the frequency of the deamon plugin in seconds.
-        """
-        raise NotImplementedError("frequency is not implemented")
+    """
+    Return the frequency in seconds of execution for this demaon plugin. Default: 60 seconds.
+    This value cannot be changed once the plugin is started.
+    """
+    deamon_frequency = 60
 
     def deamon_run(self):
         """
@@ -451,35 +449,44 @@ class JobPlugin(IDeamonPlugin):
     Sub class should implement `job_execution_time` and `job_run`.
     """
 
-    deamon_frequency = 300
-
     job_execution_time = '23:00'
 
     _next_execution_time = None
 
     def deamon_run(self):
-        # Determine the next execution time.
-        if not self._next_execution_time:
-            self._next_execution_time = self._compute_next_execution_time()
-
-        # Check if task should be run.
-        now = datetime.datetime.now()
-        if now < self._next_execution_time:
-            return
-
+        self._wait()
         # Run job.
         try:
             self.job_run()
         finally:
             self._next_execution_time = None
 
-    def _compute_next_execution_time(self):
+    def job_run(self):
+        """
+        Sub-class should implement this function.
+        """
+        raise NotImplementedError("job_run is not implemented")
+
+    def _wait(self):
+        """
+        Sleep until time to execute the job.
+        """
+        now = datetime.datetime.now()
+        t = self._get_next_execution_time()
+        time.sleep(t - now)
+
+    def _get_next_execution_time(self):
         """
         Return a date time representing the next execution time.
         """
+        try:
+            time_str = self.job_execution_time
+            exec_time = datetime.datetime.strptime(time_str, '%H:%M')
+        except:
+            logger.error("invalid execution time [%s], check your config. Using default value.", self.job_execution_time)
+            exec_time = datetime.datetime.strptime("23:00", '%H:%M')
+
         now = datetime.datetime.now()
-        time_str = self.job_execution_time
-        exec_time = datetime.datetime.strptime(time_str, '%H:%M')
         exec_time = now.replace(hour=exec_time.hour, minute=exec_time.minute, second=0, microsecond=0)
         if exec_time < now:
             exec_time = exec_time.replace(day=exec_time.day + 1)
diff --git a/rdiffweb/tests/test_rdw_plugins.py b/rdiffweb/tests/test_rdw_plugins.py
index 21d07d8464f3e3dbb4db6bd8e82cb8e33d305593..612b73fdc89209df70f6d1e9621c74c0d7add1f7 100644
--- a/rdiffweb/tests/test_rdw_plugins.py
+++ b/rdiffweb/tests/test_rdw_plugins.py
@@ -23,10 +23,13 @@ Created on Jan 29, 2015
 
 from __future__ import unicode_literals
 
+import datetime
+from mock.mock import Mock, MagicMock
 import unittest
 
+from rdiffweb import rdw_plugin
 from rdiffweb.rdw_config import Configuration
-from rdiffweb.rdw_plugin import PluginManager
+from rdiffweb.rdw_plugin import PluginManager, JobPlugin
 
 
 class PluginManagerTest(unittest.TestCase):
@@ -51,6 +54,40 @@ class PluginManagerTest(unittest.TestCase):
         self.assertEqual('GPLv3', plugin_info.copyright)
 
 
+class JobPluginTest(unittest.TestCase):
+
+    def test_get_next_execution_time(self):
+        """
+        Check JobPLugin execution time.
+        """
+        p = JobPlugin()
+        p.job_execution_time = '2:00'
+        t = p._get_next_execution_time()
+        self.assertIsInstance(t, datetime.datetime)
+
+    def test_get_next_execution_time_invalid(self):
+        """
+        Check JobPLugin execution time with invalid value.
+        """
+        p = JobPlugin()
+        p.job_execution_time = '390'
+        t1 = p._get_next_execution_time()
+        p.job_execution_time = '23:00'
+        t2 = p._get_next_execution_time()
+        self.assertEqual(t1, t2)
+
+    def test_deamon_run(self):
+        """
+        Check JobPlugin execution.
+        """
+        rdw_plugin.time.sleep = MagicMock()
+        p = JobPlugin()
+        p.job_execution_time = '23:00'
+        p.job_run = lambda: "c"
+        p.deamon_run()
+        assert rdw_plugin.time.sleep.called
+
+
 if __name__ == "__main__":
     # import sys;sys.argv = ['', 'Test.testName']
     unittest.main()