diff --git a/ceilometer/alarm/evaluator/__init__.py b/ceilometer/alarm/evaluator/__init__.py
index 856b16fb3..cfc0fee21 100644
--- a/ceilometer/alarm/evaluator/__init__.py
+++ b/ceilometer/alarm/evaluator/__init__.py
@@ -18,6 +18,9 @@
 
 
 import abc
+import croniter
+import datetime
+import pytz
 
 from ceilometerclient import client as ceiloclient
 from oslo.config import cfg
@@ -25,6 +28,7 @@ import six
 
 from ceilometer.openstack.common.gettextutils import _  # noqa
 from ceilometer.openstack.common import log
+from ceilometer.openstack.common import timeutils
 
 LOG = log.getLogger(__name__)
 
@@ -77,6 +81,39 @@ class Evaluator(object):
             # cycle (unless alarm state reverts in the meantime)
             LOG.exception(_('alarm state update failed'))
 
+    @classmethod
+    def within_time_constraint(cls, alarm):
+        """Check whether the alarm is within at least one of its time
+        constraints. If there are none, then the answer is yes.
+        """
+        if not alarm.time_constraints:
+            return True
+
+        now_utc = timeutils.utcnow()
+        for tc in alarm.time_constraints:
+            tz = pytz.timezone(tc['timezone']) if tc['timezone'] else None
+            now_tz = now_utc.astimezone(tz) if tz else now_utc
+            start_cron = croniter.croniter(tc['start'], now_tz)
+            if cls._is_exact_match(start_cron, now_tz):
+                return True
+            latest_start = start_cron.get_prev(datetime.datetime)
+            duration = datetime.timedelta(seconds=tc['duration'])
+            if latest_start <= now_tz <= latest_start + duration:
+                return True
+        return False
+
+    @staticmethod
+    def _is_exact_match(cron, ts):
+        """Handle edge case where if the timestamp is the same as the
+        cron point in time to the minute, croniter returns the previous
+        start, not the current. We can check this by first going one
+        step back and then one step forward and check if we are
+        at the original point in time.
+        """
+        cron.get_prev()
+        diff = timeutils.total_seconds(ts - cron.get_next(datetime.datetime))
+        return abs(diff) < 60  # minute precision
+
     @abc.abstractmethod
     def evaluate(self, alarm):
         '''interface definition
diff --git a/ceilometer/alarm/evaluator/combination.py b/ceilometer/alarm/evaluator/combination.py
index 7f0a18881..9fc03d192 100644
--- a/ceilometer/alarm/evaluator/combination.py
+++ b/ceilometer/alarm/evaluator/combination.py
@@ -96,6 +96,11 @@ class CombinationEvaluator(evaluator.Evaluator):
             self._refresh(alarm, state, reason, reason_data)
 
     def evaluate(self, alarm):
+        if not self.within_time_constraint(alarm):
+            LOG.debug(_('Attempted to evaluate alarm %s, but it is not '
+                        'within its time constraint.') % alarm.alarm_id)
+            return
+
         states = zip(alarm.rule['alarm_ids'],
                      itertools.imap(self._get_alarm_state,
                                     alarm.rule['alarm_ids']))
diff --git a/ceilometer/alarm/evaluator/threshold.py b/ceilometer/alarm/evaluator/threshold.py
index 6902603e5..08bd85375 100644
--- a/ceilometer/alarm/evaluator/threshold.py
+++ b/ceilometer/alarm/evaluator/threshold.py
@@ -173,6 +173,11 @@ class ThresholdEvaluator(evaluator.Evaluator):
             self._refresh(alarm, state, reason, reason_data)
 
     def evaluate(self, alarm):
+        if not self.within_time_constraint(alarm):
+            LOG.debug(_('Attempted to evaluate alarm %s, but it is not '
+                        'within its time constraint.') % alarm.alarm_id)
+            return
+
         query = self._bound_duration(
             alarm,
             alarm.rule['query']
diff --git a/ceilometer/api/controllers/v2.py b/ceilometer/api/controllers/v2.py
index dc6d74cda..49fb02643 100644
--- a/ceilometer/api/controllers/v2.py
+++ b/ceilometer/api/controllers/v2.py
@@ -28,11 +28,13 @@
 import ast
 import base64
 import copy
+import croniter
 import datetime
 import functools
 import inspect
 import json
 import jsonschema
+import pytz
 import uuid
 
 from oslo.config import cfg
@@ -108,6 +110,18 @@ class AdvEnum(wtypes.wsproperty):
             setattr(parent, self._name, value)
 
 
+class CronType(wtypes.UserType):
+    """A user type that represents a cron format."""
+    basetype = six.string_types
+    name = 'cron'
+
+    @staticmethod
+    def validate(value):
+        # raises ValueError if invalid
+        croniter.croniter(value)
+        return value
+
+
 class _Base(wtypes.Base):
 
     @classmethod
@@ -1479,6 +1493,59 @@ class AlarmCombinationRule(_Base):
                               '153462d0-a9b8-4b5b-8175-9e4b05e9b856'])
 
 
+class AlarmTimeConstraint(_Base):
+    """Representation of a time constraint on an alarm."""
+
+    name = wsme.wsattr(wtypes.text, mandatory=True)
+    "The name of the constraint"
+
+    _description = None  # provide a default
+
+    def get_description(self):
+        if not self._description:
+            return 'Time constraint at %s lasting for %s seconds' \
+                   % (self.start, self.duration)
+        return self._description
+
+    def set_description(self, value):
+        self._description = value
+
+    description = wsme.wsproperty(wtypes.text, get_description,
+                                  set_description)
+    "The description of the constraint"
+
+    start = wsme.wsattr(CronType(), mandatory=True)
+    "Start point of the time constraint, in cron format"
+
+    duration = wsme.wsattr(wtypes.IntegerType(minimum=0), mandatory=True)
+    "How long the constraint should last, in seconds"
+
+    timezone = wsme.wsattr(wtypes.text, default="")
+    "Timezone of the constraint"
+
+    def as_dict(self):
+        return self.as_dict_from_keys(['name', 'description', 'start',
+                                       'duration', 'timezone'])
+
+    @staticmethod
+    def validate(tc):
+        if tc.timezone:
+            try:
+                pytz.timezone(tc.timezone)
+            except Exception:
+                raise ClientSideError(_("Timezone %s is not valid")
+                                      % tc.timezone)
+        return tc
+
+    @classmethod
+    def sample(cls):
+        return cls(name='SampleConstraint',
+                   description='nightly build every night at 23h for 3 hours',
+                   start='0 23 * * *',
+                   duration=10800,
+                   timezone='Europe/Ljubljana')
+
+
 class Alarm(_Base):
     """Representation of an alarm.
 
@@ -1534,6 +1601,9 @@ class Alarm(_Base):
     """Describe when to trigger the alarm based on combining the state of
     other alarms"""
 
+    time_constraints = wtypes.wsattr([AlarmTimeConstraint], default=[])
+    """Describe time constraints for the alarm"""
+
     # These settings are ignored in the PUT or POST operations, but are
     # filled in for GET
     project_id = wtypes.text
@@ -1552,7 +1622,7 @@ class Alarm(_Base):
     state_timestamp = datetime.datetime
     "The date of the last alarm state changed"
 
-    def __init__(self, rule=None, **kwargs):
+    def __init__(self, rule=None, time_constraints=None, **kwargs):
         super(Alarm, self).__init__(**kwargs)
 
         if rule:
@@ -1560,6 +1630,9 @@ class Alarm(_Base):
                 self.threshold_rule = AlarmThresholdRule(**rule)
             elif self.type == 'combination':
                 self.combination_rule = AlarmCombinationRule(**rule)
+        if time_constraints:
+            self.time_constraints = [AlarmTimeConstraint(**tc)
+                                     for tc in time_constraints]
 
     @staticmethod
     def validate(alarm):
@@ -1602,6 +1675,7 @@ class Alarm(_Base):
                    type='combination',
                    threshold_rule=None,
                    combination_rule=AlarmCombinationRule.sample(),
+                   time_constraints=[AlarmTimeConstraint.sample().as_dict()],
                    user_id="c96c887c216949acbdfbd8b494863567",
                    project_id="c96c887c216949acbdfbd8b494863567",
                    enabled=True,
@@ -1620,6 +1694,7 @@ class Alarm(_Base):
             if k.endswith('_rule'):
                 del d[k]
         d['rule'] = getattr(self, "%s_rule" % self.type).as_dict()
+        d['time_constraints'] = [tc.as_dict() for tc in self.time_constraints]
         return d
 
 
diff --git a/ceilometer/storage/impl_sqlalchemy.py b/ceilometer/storage/impl_sqlalchemy.py
index 3c1cd8a02..e7881807a 100644
--- a/ceilometer/storage/impl_sqlalchemy.py
+++ b/ceilometer/storage/impl_sqlalchemy.py
@@ -746,6 +746,7 @@ class Connection(base.Connection):
                                 insufficient_data_actions=
                                 row.insufficient_data_actions,
                                 rule=row.rule,
+                                time_constraints=row.time_constraints,
                                 repeat_actions=row.repeat_actions)
 
     def _retrieve_alarms(self, query):
diff --git a/ceilometer/storage/models.py b/ceilometer/storage/models.py
index dbcee3367..7939c07ce 100644
--- a/ceilometer/storage/models.py
+++ b/ceilometer/storage/models.py
@@ -298,6 +298,7 @@ class Alarm(Model):
     :param project_id: the project_id of the creator
     :param evaluation_periods: the number of periods
     :param period: the time period in seconds
+    :param time_constraints: the list of the alarm's time constraints, if any
     :param timestamp: the timestamp when the alarm was last updated
     :param state_timestamp: the timestamp of the last state change
     :param ok_actions: the list of webhooks to call when entering the ok state
@@ -311,7 +312,7 @@ class Alarm(Model):
     def __init__(self, alarm_id, type, enabled, name, description,
                  timestamp, user_id, project_id, state, state_timestamp,
                  ok_actions, alarm_actions, insufficient_data_actions,
-                 repeat_actions, rule):
+                 repeat_actions, rule, time_constraints):
         Model.__init__(
             self,
             alarm_id=alarm_id,
@@ -329,7 +330,8 @@ class Alarm(Model):
             insufficient_data_actions=
             insufficient_data_actions,
             repeat_actions=repeat_actions,
-            rule=rule)
+            rule=rule,
+            time_constraints=time_constraints)
 
 
 class AlarmChange(Model):
diff --git a/ceilometer/storage/pymongo_base.py b/ceilometer/storage/pymongo_base.py
index 9556d58cb..82fe07933 100644
--- a/ceilometer/storage/pymongo_base.py
+++ b/ceilometer/storage/pymongo_base.py
@@ -209,6 +209,7 @@ class Connection(base.Connection):
         stored_alarm = self.db.alarm.find({'alarm_id': alarm.alarm_id})[0]
         del stored_alarm['_id']
         self._ensure_encapsulated_rule_format(stored_alarm)
+        self._ensure_time_constraints(stored_alarm)
         return models.Alarm(**stored_alarm)
 
     create_alarm = update_alarm
@@ -317,6 +318,7 @@ class Connection(base.Connection):
             a.update(alarm)
             del a['_id']
             self._ensure_encapsulated_rule_format(a)
+            self._ensure_time_constraints(a)
             yield models.Alarm(**a)
 
     def _retrieve_alarm_changes(self, query_filter, orderby, limit):
@@ -397,6 +399,12 @@ class Connection(base.Connection):
                 new_matching_metadata[elem['key']] = elem['value']
             return new_matching_metadata
 
+    @staticmethod
+    def _ensure_time_constraints(alarm):
+        """Ensures the alarm has a time constraints field."""
+        if 'time_constraints' not in alarm:
+            alarm['time_constraints'] = []
+
 
 class QueryTransformer(object):
 
diff --git a/ceilometer/storage/sqlalchemy/migrate_repo/versions/032_add_alarm_time_constraints.py b/ceilometer/storage/sqlalchemy/migrate_repo/versions/032_add_alarm_time_constraints.py
new file mode 100644
index 000000000..cbc577ee4
--- /dev/null
+++ b/ceilometer/storage/sqlalchemy/migrate_repo/versions/032_add_alarm_time_constraints.py
@@ -0,0 +1,34 @@
+# -*- encoding: utf-8 -*-
+#
+# Author: Nejc Saje <nejc.saje@xlab.si>
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from sqlalchemy import Column
+from sqlalchemy import MetaData
+from sqlalchemy import Table
+from sqlalchemy import Text
+
+
+def upgrade(migrate_engine):
+    meta = MetaData(bind=migrate_engine)
+    alarm = Table('alarm', meta, autoload=True)
+    time_constraints = Column('time_constraints', Text())
+    alarm.create_column(time_constraints)
+
+
+def downgrade(migrate_engine):
+    meta = MetaData(bind=migrate_engine)
+    alarm = Table('alarm', meta, autoload=True)
+    time_constraints = Column('time_constraints', Text())
+    alarm.drop_column(time_constraints)
diff --git a/ceilometer/storage/sqlalchemy/models.py b/ceilometer/storage/sqlalchemy/models.py
index 6ce20d6b3..c3ad5c9a4 100644
--- a/ceilometer/storage/sqlalchemy/models.py
+++ b/ceilometer/storage/sqlalchemy/models.py
@@ -309,6 +309,7 @@ class Alarm(Base):
     repeat_actions = Column(Boolean)
 
     rule = Column(JSONEncodedDict)
+    time_constraints = Column(JSONEncodedDict)
 
 
 class AlarmChange(Base):
diff --git a/ceilometer/tests/alarm/evaluator/test_base.py b/ceilometer/tests/alarm/evaluator/test_base.py
index 925eb7f8b..031785fd7 100644
--- a/ceilometer/tests/alarm/evaluator/test_base.py
+++ b/ceilometer/tests/alarm/evaluator/test_base.py
@@ -17,10 +17,13 @@
 # under the License.
 """class for tests in ceilometer/alarm/evaluator/__init__.py
 """
+import datetime
 import mock
+import pytz
 
 from ceilometer.alarm import evaluator
 from ceilometer.openstack.common import test
+from ceilometer.openstack.common import timeutils
 
 
 class TestEvaluatorBaseClass(test.BaseTestCase):
@@ -45,3 +48,92 @@ class TestEvaluatorBaseClass(test.BaseTestCase):
         ev._refresh(mock.MagicMock(), mock.MagicMock(),
                     mock.MagicMock(), mock.MagicMock())
         self.assertTrue(self.called)
+
+    def test_base_time_constraints(self):
+        alarm = mock.MagicMock()
+        alarm.time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             'start': '0 11 * * *',  # daily at 11:00
+             'duration': 10800,  # 3 hours
+             'timezone': ''},
+            {'name': 'test2',
+             'description': 'test',
+             'start': '0 23 * * *',  # daily at 23:00
+             'duration': 10800,  # 3 hours
+             'timezone': ''},
+        ]
+        cls = evaluator.Evaluator
+        timeutils.set_time_override(datetime.datetime(2014, 1, 1, 12, 0, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+
+        timeutils.set_time_override(datetime.datetime(2014, 1, 2, 1, 0, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+
+        timeutils.set_time_override(datetime.datetime(2014, 1, 2, 5, 0, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+
+    def test_base_time_constraints_complex(self):
+        alarm = mock.MagicMock()
+        alarm.time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             # Every consecutive 2 minutes (from the 3rd to the 57th) past
+             # every consecutive 2 hours (between 3:00 and 12:59) on every day.
+             'start': '3-57/2 3-12/2 * * *',
+             'duration': 30,
+             'timezone': ''}
+        ]
+        cls = evaluator.Evaluator
+
+        # test minutes inside
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 3, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 31, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 57, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+
+        # test minutes outside
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 2, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 4, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 58, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+
+        # test hours inside
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 3, 31, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 5, 31, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 11, 31, 0))
+        self.assertTrue(cls.within_time_constraint(alarm))
+
+        # test hours outside
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 1, 31, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 4, 31, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+        timeutils.set_time_override(datetime.datetime(2014, 1, 5, 12, 31, 0))
+        self.assertFalse(cls.within_time_constraint(alarm))
+
+    def test_base_time_constraints_timezone(self):
+        alarm = mock.MagicMock()
+        alarm.time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             'start': '0 11 * * *',  # daily at 11:00
+             'duration': 10800,  # 3 hours
+             'timezone': 'Europe/Ljubljana'}
+        ]
+        cls = evaluator.Evaluator
+        dt_eu = datetime.datetime(2014, 1, 1, 12, 0, 0,
+                                  tzinfo=pytz.timezone('Europe/Ljubljana'))
+        dt_us = datetime.datetime(2014, 1, 1, 12, 0, 0,
+                                  tzinfo=pytz.timezone('US/Eastern'))
+        timeutils.set_time_override(dt_eu.astimezone(pytz.UTC))
+        self.assertTrue(cls.within_time_constraint(alarm))
+
+        timeutils.set_time_override(dt_us.astimezone(pytz.UTC))
+        self.assertFalse(cls.within_time_constraint(alarm))
diff --git a/ceilometer/tests/alarm/evaluator/test_combination.py b/ceilometer/tests/alarm/evaluator/test_combination.py
index 8565ec172..34d1b206a 100644
--- a/ceilometer/tests/alarm/evaluator/test_combination.py
+++ b/ceilometer/tests/alarm/evaluator/test_combination.py
@@ -17,10 +17,13 @@
 # under the License.
 """Tests for ceilometer/alarm/threshold_evaluation.py
 """
+import datetime
 import mock
+import pytz
 import uuid
 
 from ceilometer.alarm.evaluator import combination
+from ceilometer.openstack.common import timeutils
 from ceilometer.storage import models
 from ceilometer.tests.alarm.evaluator import base
 from ceilometerclient import exc
@@ -46,6 +49,7 @@ class TestEvaluate(base.TestEvaluatorBase):
                          ok_actions=[],
                          alarm_actions=[],
                          repeat_actions=False,
+                         time_constraints=[],
                          rule=dict(
                              alarm_ids=[
                                  '9cfc3e51-2ff1-4b1d-ac01-c1bd4c6d0d1e',
@@ -66,6 +70,7 @@ class TestEvaluate(base.TestEvaluatorBase):
                          ok_actions=[],
                          alarm_actions=[],
                          repeat_actions=False,
+                         time_constraints=[],
                          rule=dict(
                              alarm_ids=[
                                  'b82734f4-9d06-48f3-8a86-fa59a0c99dc8',
@@ -304,3 +309,69 @@ class TestEvaluate(base.TestEvaluatorBase):
                         in zip(self.alarms, reasons, reason_datas)]
 
             self.assertEqual(self.notifier.notify.call_args_list, expected)
+
+    def test_state_change_inside_time_constraint(self):
+        self._set_all_alarms('insufficient data')
+        self.alarms[0].time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             'start': '0 11 * * *',  # daily at 11:00
+             'duration': 10800,  # 3 hours
+             'timezone': 'Europe/Ljubljana'}
+        ]
+        self.alarms[1].time_constraints = self.alarms[0].time_constraints
+        dt = datetime.datetime(2014, 1, 1, 12, 0, 0,
+                               tzinfo=pytz.timezone('Europe/Ljubljana'))
+        with mock.patch('ceilometerclient.client.get_client',
+                        return_value=self.api_client):
+            timeutils.set_time_override(dt.astimezone(pytz.UTC))
+            self.api_client.alarms.get.side_effect = [
+                self._get_alarm('ok'),
+                self._get_alarm('ok'),
+                self._get_alarm('ok'),
+                self._get_alarm('ok'),
+            ]
+            self._evaluate_all_alarms()
+            expected = [mock.call(alarm.alarm_id, state='ok')
+                        for alarm in self.alarms]
+            update_calls = self.api_client.alarms.set_state.call_args_list
+            self.assertEqual(expected, update_calls,
+                             "Alarm should change state if the current "
+                             "time is inside its time constraint.")
+            reasons, reason_datas = self._combination_transition_reason(
+                'ok',
+                self.alarms[0].rule['alarm_ids'],
+                self.alarms[1].rule['alarm_ids'])
+            expected = [mock.call(alarm, 'insufficient data',
+                                  reason, reason_data)
+                        for alarm, reason, reason_data
+                        in zip(self.alarms, reasons, reason_datas)]
+            self.assertEqual(expected, self.notifier.notify.call_args_list)
+
+    def test_no_state_change_outside_time_constraint(self):
+        self._set_all_alarms('insufficient data')
+        self.alarms[0].time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             'start': '0 11 * * *',  # daily at 11:00
+             'duration': 10800,  # 3 hours
+             'timezone': 'Europe/Ljubljana'}
+        ]
+        self.alarms[1].time_constraints = self.alarms[0].time_constraints
+        dt = datetime.datetime(2014, 1, 1, 15, 0, 0,
+                               tzinfo=pytz.timezone('Europe/Ljubljana'))
+        with mock.patch('ceilometerclient.client.get_client',
+                        return_value=self.api_client):
+            timeutils.set_time_override(dt.astimezone(pytz.UTC))
+            self.api_client.alarms.get.side_effect = [
+                self._get_alarm('ok'),
+                self._get_alarm('ok'),
+                self._get_alarm('ok'),
+                self._get_alarm('ok'),
+            ]
+            self._evaluate_all_alarms()
+            update_calls = self.api_client.alarms.set_state.call_args_list
+            self.assertEqual([], update_calls,
+                             "Alarm should not change state if the current "
+                             " time is outside its time constraint.")
+            self.assertEqual([], self.notifier.notify.call_args_list)
diff --git a/ceilometer/tests/alarm/evaluator/test_threshold.py b/ceilometer/tests/alarm/evaluator/test_threshold.py
index 6abaa2395..ba429eb4d 100644
--- a/ceilometer/tests/alarm/evaluator/test_threshold.py
+++ b/ceilometer/tests/alarm/evaluator/test_threshold.py
@@ -19,6 +19,7 @@
 """
 import datetime
 import mock
+import pytz
 import uuid
 
 from six import moves
@@ -51,6 +52,7 @@ class TestEvaluate(base.TestEvaluatorBase):
                          ok_actions=[],
                          alarm_actions=[],
                          repeat_actions=False,
+                         time_constraints=[],
                          rule=dict(
                              comparison_operator='gt',
                              threshold=80.0,
@@ -79,6 +81,7 @@ class TestEvaluate(base.TestEvaluatorBase):
                          alarm_actions=[],
                          repeat_actions=False,
                          alarm_id=str(uuid.uuid4()),
+                         time_constraints=[],
                          rule=dict(
                              comparison_operator='le',
                              threshold=10.0,
@@ -438,3 +441,64 @@ class TestEvaluate(base.TestEvaluatorBase):
 
     def test_simple_alarm_no_clear_without_outlier_exclusion(self):
         self. _do_test_simple_alarm_clear_outlier_exclusion(False)
+
+    def test_state_change_inside_time_constraint(self):
+        self._set_all_alarms('ok')
+        self.alarms[0].time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             'start': '0 11 * * *',  # daily at 11:00
+             'duration': 10800,  # 3 hours
+             'timezone': 'Europe/Ljubljana'}
+        ]
+        self.alarms[1].time_constraints = self.alarms[0].time_constraints
+        dt = datetime.datetime(2014, 1, 1, 12, 0, 0,
+                               tzinfo=pytz.timezone('Europe/Ljubljana'))
+        with mock.patch('ceilometerclient.client.get_client',
+                        return_value=self.api_client):
+            timeutils.set_time_override(dt.astimezone(pytz.UTC))
+            # the following part based on test_simple_insufficient
+            self.api_client.statistics.list.return_value = []
+            self._evaluate_all_alarms()
+            self._assert_all_alarms('insufficient data')
+            expected = [mock.call(alarm.alarm_id,
+                                  state='insufficient data')
+                        for alarm in self.alarms]
+            update_calls = self.api_client.alarms.set_state.call_args_list
+            self.assertEqual(expected, update_calls,
+                             "Alarm should change state if the current "
+                             "time is inside its time constraint.")
+            expected = [mock.call(
+                alarm,
+                'ok',
+                ('%d datapoints are unknown'
+                 % alarm.rule['evaluation_periods']),
+                self._reason_data('unknown',
+                                  alarm.rule['evaluation_periods'],
+                                  None))
+                for alarm in self.alarms]
+            self.assertEqual(expected, self.notifier.notify.call_args_list)
+
+    def test_no_state_change_outside_time_constraint(self):
+        self._set_all_alarms('ok')
+        self.alarms[0].time_constraints = [
+            {'name': 'test',
+             'description': 'test',
+             'start': '0 11 * * *',  # daily at 11:00
+             'duration': 10800,  # 3 hours
+             'timezone': 'Europe/Ljubljana'}
+        ]
+        self.alarms[1].time_constraints = self.alarms[0].time_constraints
+        dt = datetime.datetime(2014, 1, 1, 15, 0, 0,
+                               tzinfo=pytz.timezone('Europe/Ljubljana'))
+        with mock.patch('ceilometerclient.client.get_client',
+                        return_value=self.api_client):
+            timeutils.set_time_override(dt.astimezone(pytz.UTC))
+            self.api_client.statistics.list.return_value = []
+            self._evaluate_all_alarms()
+            self._assert_all_alarms('ok')
+            update_calls = self.api_client.alarms.set_state.call_args_list
+            self.assertEqual([], update_calls,
+                             "Alarm should not change state if the current "
+                             " time is outside its time constraint.")
+            self.assertEqual([], self.notifier.notify.call_args_list)
diff --git a/ceilometer/tests/alarm/partition/test_coordination.py b/ceilometer/tests/alarm/partition/test_coordination.py
index 7f814e47e..174f3d23a 100644
--- a/ceilometer/tests/alarm/partition/test_coordination.py
+++ b/ceilometer/tests/alarm/partition/test_coordination.py
@@ -100,6 +100,7 @@ class TestCoordinate(test.BaseTestCase):
                             alarm_actions=[],
                             insufficient_data_actions=[],
                             alarm_id=uuid,
+                            time_constraints=[],
                             rule=dict(
                                 statistic='avg',
                                 comparison_operator='gt',
diff --git a/ceilometer/tests/api/v2/test_alarm_scenarios.py b/ceilometer/tests/api/v2/test_alarm_scenarios.py
index 65c95dfdb..60920e66f 100644
--- a/ceilometer/tests/api/v2/test_alarm_scenarios.py
+++ b/ceilometer/tests/api/v2/test_alarm_scenarios.py
@@ -70,6 +70,9 @@ class TestAlarms(FunctionalTest,
                          repeat_actions=True,
                          user_id=self.auth_headers['X-User-Id'],
                          project_id=self.auth_headers['X-Project-Id'],
+                         time_constraints=[dict(name='testcons',
+                                                start='0 11 * * *',
+                                                duration=300)],
                          rule=dict(comparison_operator='gt',
                                    threshold=2.0,
                                    statistic='avg',
@@ -95,6 +98,7 @@ class TestAlarms(FunctionalTest,
                          repeat_actions=False,
                          user_id=self.auth_headers['X-User-Id'],
                          project_id=self.auth_headers['X-Project-Id'],
+                         time_constraints=[],
                          rule=dict(comparison_operator='gt',
                                    threshold=4.0,
                                    statistic='avg',
@@ -120,6 +124,7 @@ class TestAlarms(FunctionalTest,
                          repeat_actions=False,
                          user_id=self.auth_headers['X-User-Id'],
                          project_id=self.auth_headers['X-Project-Id'],
+                         time_constraints=[],
                          rule=dict(comparison_operator='gt',
                                    threshold=3.0,
                                    statistic='avg',
@@ -145,6 +150,7 @@ class TestAlarms(FunctionalTest,
                          repeat_actions=False,
                          user_id=self.auth_headers['X-User-Id'],
                          project_id=self.auth_headers['X-Project-Id'],
+                         time_constraints=[],
                          rule=dict(alarm_ids=['a', 'b'],
                                    operator='or')
                          )]:
@@ -215,6 +221,8 @@ class TestAlarms(FunctionalTest,
                          'meter.test')
         self.assertEqual(one['alarm_id'], alarms[0]['alarm_id'])
         self.assertEqual(one['repeat_actions'], alarms[0]['repeat_actions'])
+        self.assertEqual(one['time_constraints'],
+                         alarms[0]['time_constraints'])
 
     def test_get_alarm_disabled(self):
         alarm = models.Alarm(name='disabled',
@@ -231,6 +239,7 @@ class TestAlarms(FunctionalTest,
                              repeat_actions=False,
                              user_id=self.auth_headers['X-User-Id'],
                              project_id=self.auth_headers['X-Project-Id'],
+                             time_constraints=[],
                              rule=dict(alarm_ids=['a', 'b'], operator='or'))
         self.conn.update_alarm(alarm)
 
@@ -308,6 +317,70 @@ class TestAlarms(FunctionalTest,
         alarms = list(self.conn.get_alarms())
         self.assertEqual(4, len(alarms))
 
+    def test_post_invalid_alarm_time_constraint_start(self):
+        json = {
+            'name': 'added_alarm_invalid_constraint_duration',
+            'type': 'threshold',
+            'time_constraints': [
+                {
+                    'name': 'testcons',
+                    'start': '11:00am',
+                    'duration': 10
+                }
+            ],
+            'threshold_rule': {
+                'meter_name': 'ameter',
+                'threshold': 300.0
+            }
+        }
+        self.post_json('/alarms', params=json, expect_errors=True, status=400,
+                       headers=self.auth_headers)
+        alarms = list(self.conn.get_alarms())
+        self.assertEqual(4, len(alarms))
+
+    def test_post_invalid_alarm_time_constraint_duration(self):
+        json = {
+            'name': 'added_alarm_invalid_constraint_duration',
+            'type': 'threshold',
+            'time_constraints': [
+                {
+                    'name': 'testcons',
+                    'start': '* 11 * * *',
+                    'duration': -1,
+                }
+            ],
+            'threshold_rule': {
+                'meter_name': 'ameter',
+                'threshold': 300.0
+            }
+        }
+        self.post_json('/alarms', params=json, expect_errors=True, status=400,
+                       headers=self.auth_headers)
+        alarms = list(self.conn.get_alarms())
+        self.assertEqual(4, len(alarms))
+
+    def test_post_invalid_alarm_time_constraint_timezone(self):
+        json = {
+            'name': 'added_alarm_invalid_constraint_timezone',
+            'type': 'threshold',
+            'time_constraints': [
+                {
+                    'name': 'testcons',
+                    'start': '* 11 * * *',
+                    'duration': 10,
+                    'timezone': 'aaaa'
+                }
+            ],
+            'threshold_rule': {
+                'meter_name': 'ameter',
+                'threshold': 300.0
+            }
+        }
+        self.post_json('/alarms', params=json, expect_errors=True, status=400,
+                       headers=self.auth_headers)
+        alarms = list(self.conn.get_alarms())
+        self.assertEqual(4, len(alarms))
+
     def test_post_invalid_alarm_period(self):
         json = {
             'name': 'added_alarm_invalid_period',
@@ -1120,8 +1193,9 @@ class TestAlarms(FunctionalTest,
         self.assertIsNotNone(actual['event_id'])
 
     def _assert_in_json(self, expected, actual):
+        actual = jsonutils.dumps(jsonutils.loads(actual), sort_keys=True)
         for k, v in expected.iteritems():
-            fragment = jsonutils.dumps({k: v})[1:-1]
+            fragment = jsonutils.dumps({k: v}, sort_keys=True)[1:-1]
             self.assertTrue(fragment in actual,
                             '%s not in %s' % (fragment, actual))
 
diff --git a/ceilometer/tests/api/v2/test_complex_query_scenarios.py b/ceilometer/tests/api/v2/test_complex_query_scenarios.py
index 8cf5b8d3a..e38364b49 100644
--- a/ceilometer/tests/api/v2/test_complex_query_scenarios.py
+++ b/ceilometer/tests/api/v2/test_complex_query_scenarios.py
@@ -301,6 +301,7 @@ class TestQueryAlarmsController(tests_api.FunctionalTest,
                                          repeat_actions=True,
                                          user_id="user-id%d" % id,
                                          project_id=project_id,
+                                         time_constraints=[],
                                          rule=dict(comparison_operator='gt',
                                                    threshold=2.0,
                                                    statistic='avg',
diff --git a/ceilometer/tests/storage/test_impl_mongodb.py b/ceilometer/tests/storage/test_impl_mongodb.py
index d7d70d595..02709e5bc 100644
--- a/ceilometer/tests/storage/test_impl_mongodb.py
+++ b/ceilometer/tests/storage/test_impl_mongodb.py
@@ -256,6 +256,10 @@ class CompatibilityTest(test_storage_scenarios.DBTestBase,
         self.assertEqual(old.rule['comparison_operator'], 'lt')
         self.assertEqual(old.rule['threshold'], 36)
 
+    def test_alarm_without_time_constraints(self):
+        old = list(self.conn.get_alarms(name='other-old-alaert'))[0]
+        self.assertEqual([], old.time_constraints)
+
     def test_counter_unit(self):
         meters = list(self.conn.get_meters())
         self.assertEqual(len(meters), 1)
diff --git a/ceilometer/tests/storage/test_models.py b/ceilometer/tests/storage/test_models.py
index 2aea7561e..dde64806f 100644
--- a/ceilometer/tests/storage/test_models.py
+++ b/ceilometer/tests/storage/test_models.py
@@ -71,7 +71,8 @@ class ModelTest(test.BaseTestCase):
         alarm_fields = ["alarm_id", "type", "enabled", "name", "description",
                         "timestamp", "user_id", "project_id", "state",
                         "state_timestamp", "ok_actions", "alarm_actions",
-                        "insufficient_data_actions", "repeat_actions", "rule"]
+                        "insufficient_data_actions", "repeat_actions", "rule",
+                        "time_constraints"]
 
         self.assertEqual(set(alarm_fields),
                          set(models.Alarm.get_field_names()))
diff --git a/ceilometer/tests/storage/test_storage_scenarios.py b/ceilometer/tests/storage/test_storage_scenarios.py
index e173a4133..726bc9c4b 100644
--- a/ceilometer/tests/storage/test_storage_scenarios.py
+++ b/ceilometer/tests/storage/test_storage_scenarios.py
@@ -696,6 +696,7 @@ class RawSampleTest(DBTestBase,
                              alarm_actions=['http://nowhere/alarms'],
                              insufficient_data_actions=[],
                              repeat_actions=False,
+                             time_constraints=[],
                              rule=dict(comparison_operator='eq',
                                        threshold=36,
                                        statistic='count',
@@ -2312,6 +2313,9 @@ class AlarmTestBase(DBTestBase):
                                alarm_actions=['http://nowhere/alarms'],
                                insufficient_data_actions=[],
                                repeat_actions=False,
+                               time_constraints=[dict(name='testcons',
+                                                      start='0 11 * * *',
+                                                      duration=300)],
                                rule=dict(comparison_operator='eq',
                                          threshold=36,
                                          statistic='count',
@@ -2337,6 +2341,7 @@ class AlarmTestBase(DBTestBase):
                                alarm_actions=['http://nowhere/alarms'],
                                insufficient_data_actions=[],
                                repeat_actions=False,
+                               time_constraints=[],
                                rule=dict(comparison_operator='gt',
                                          threshold=75,
                                          statistic='avg',
@@ -2362,6 +2367,7 @@ class AlarmTestBase(DBTestBase):
                                alarm_actions=['http://nowhere/alarms'],
                                insufficient_data_actions=[],
                                repeat_actions=False,
+                               time_constraints=[],
                                rule=dict(comparison_operator='lt',
                                          threshold=10,
                                          statistic='min',
@@ -2446,6 +2452,7 @@ class AlarmTest(AlarmTestBase,
                            alarm_actions=[],
                            insufficient_data_actions=[],
                            repeat_actions=False,
+                           time_constraints=[],
                            rule=dict(comparison_operator='lt',
                                      threshold=34,
                                      statistic='max',
diff --git a/doc/source/webapi/v2.rst b/doc/source/webapi/v2.rst
index bae8358b0..89b160e18 100644
--- a/doc/source/webapi/v2.rst
+++ b/doc/source/webapi/v2.rst
@@ -57,6 +57,9 @@ Alarms
 .. autotype:: ceilometer.api.controllers.v2.AlarmCombinationRule
    :members:
 
+.. autotype:: ceilometer.api.controllers.v2.AlarmTimeConstraint
+   :members:
+
 .. autotype:: ceilometer.api.controllers.v2.AlarmChange
    :members:
 
diff --git a/requirements.txt b/requirements.txt
index 7de306ac8..a869dd83d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 alembic>=0.4.1
 anyjson>=0.3.3
 argparse
+croniter>=0.3.4
 eventlet>=0.13.0
 Flask>=0.10,<1.0
 happybase>=0.4,<=0.6
@@ -20,6 +21,7 @@ python-glanceclient>=0.9.0
 python-keystoneclient>=0.6.0
 python-novaclient>=2.15.0
 python-swiftclient>=1.6
+pytz>=2010h
 PyYAML>=3.1.0
 requests>=1.1
 six>=1.5.2