diff --git a/schedule/__init__.py b/schedule/__init__.py
index e6ebe156..63ab9ab1 100644
--- a/schedule/__init__.py
+++ b/schedule/__init__.py
@@ -42,7 +42,6 @@
 
 logger = logging.getLogger('schedule')
 
-
 class Scheduler(object):
     def __init__(self):
         self.jobs = []
@@ -83,6 +82,7 @@ def run(cls):
                     time.sleep(interval)
 
         continuous_thread = ScheduleThread()
+        continuous_thread.setDaemon(True)
         continuous_thread.start()
         return cease_continuous_run
 
@@ -111,6 +111,10 @@ def every(self, interval=1):
     @property
     def next_run(self):
         """Datetime when the next job should run."""
+        if self.jobs:
+            date_time = min(self.jobs).next_run
+        else:
+            return None
         return min(self.jobs).next_run
 
     @property
@@ -122,18 +126,19 @@ def idle_seconds(self):
 class Job(object):
     """A periodic job as used by `Scheduler`."""
     def __init__(self, interval):
-        self.interval = interval  # pause interval * unit between runs
-        self.job_func = None  # the job job_func to run
-        self.unit = None  # time units, e.g. 'minutes', 'hours', ...
-        self.at_time = None  # optional time at which this job runs
-        self.last_run = None  # datetime of the last run
-        self.next_run = None  # datetime of the next run
-        self.period = None  # timedelta between runs, only valid for
+        self.interval = interval # pause interval * unit between runs
+        self.job_func = None     # the job job_func to run
+        self.unit     = None     # time units, e.g. 'minutes', 'hours', ...
+        self.at_time  = None     # optional time at which this job runs
+        self.last_run = None     # datetime of the last run
+        self.next_run = None     # datetime of the next run
+        self.period   = None     # timedelta between runs, only valid for
+        self.paused   = False    # job paused state
 
     def __lt__(self, other):
         """PeriodicJobs are sortable based on the scheduled time
         they run next."""
-        return self.next_run < other.next_run
+        return (self.next_run < other.next_run) and (not self.paused)
 
     def __repr__(self):
         def format_time(t):
@@ -237,7 +242,7 @@ def do(self, job_func, *args, **kwargs):
     @property
     def should_run(self):
         """True if the job should be run now."""
-        return datetime.datetime.now() >= self.next_run
+        return (datetime.datetime.now() >= self.next_run) and (not self.paused)
 
     def run(self):
         """Run the job and immediately reschedule it."""
@@ -265,6 +270,13 @@ def _schedule_next_run(self):
                     self.at_time > datetime.datetime.now().time()):
                 self.next_run = self.next_run - datetime.timedelta(days=1)
 
+    def pause(self):
+        self.paused        = True
+        self.next_run_save = self.next_run - datetime.datetime.now()
+
+    def unpause(self):
+        self.paused        = False
+        self.next_run      = datetime.datetime.now() + self.next_run_save
 
 # The following methods are shortcuts for not having to
 # create a Scheduler instance:
diff --git a/test_schedule.py b/test_schedule.py
index 6f86011e..895d7254 100644
--- a/test_schedule.py
+++ b/test_schedule.py
@@ -55,6 +55,7 @@ def now(cls):
         datetime.datetime = MockDate
 
         mock_job = make_mock_job()
+        assert schedule.next_run() is None
         assert every().minute.do(mock_job).next_run.minute == 16
         assert every(5).minutes.do(mock_job).next_run.minute == 20
         assert every().hour.do(mock_job).next_run.hour == 13