diff --git a/neat/contracts_extra.py b/neat/contracts_extra.py
index 36dbe72..76ed48d 100644
--- a/neat/contracts_extra.py
+++ b/neat/contracts_extra.py
@@ -15,6 +15,7 @@
 from contracts import new_contract
 
 import collections
+import datetime
 import libvirt
 import sqlalchemy
 import neat.db
@@ -23,6 +24,7 @@ import neat.db
 
 new_contract('deque', collections.deque)
 new_contract('function', lambda x: hasattr(x, '__call__'))
+new_contract('datetime', datetime.datetime)
 new_contract('virConnect', libvirt.virConnect)
 new_contract('virDomain', libvirt.virDomain)
 new_contract('Table', sqlalchemy.Table)
diff --git a/neat/globals/db_cleaner.py b/neat/globals/db_cleaner.py
index e58df54..e449c89 100644
--- a/neat/globals/db_cleaner.py
+++ b/neat/globals/db_cleaner.py
@@ -85,4 +85,19 @@ def execute(config, state):
     :return: The updated state dictionary.
      :rtype: dict(str: *)
     """
+    datetime_threshold = today() - state['time_delta']
+    state['db'].cleanup_vm_resource_usage(datetime_threshold)
+    if log.isEnabledFor(logging.INFO):
+        log.info('Cleaned up data older than %s', 
+                 datetime_threshold.strftime('%Y-%m-%d %H:%M:%S'))
     return state
+
+
+@contract
+def today(config, state):
+    """ Return the today's datetime.
+
+    :return: A datetime object representing current date and time.
+     :rtype: datetime
+    """
+    return datetime.datetime.today()
diff --git a/tests/globals/test_db_cleaner.py b/tests/globals/test_db_cleaner.py
index a96e597..0c7cb0d 100644
--- a/tests/globals/test_db_cleaner.py
+++ b/tests/globals/test_db_cleaner.py
@@ -19,6 +19,7 @@ import datetime
 
 import neat.globals.db_cleaner as cleaner
 import neat.common as common
+import neat.db_utils as db_utils
 
 import logging
 logging.disable(logging.CRITICAL)
@@ -59,3 +60,27 @@ class DbCleaner(TestCase):
             state = cleaner.init_state(config)
             assert state['db'] == db
             assert state['time_delta'] == datetime.timedelta(0, 7200)
+
+    @qc(1)
+    def execute(
+        uuid=str_(of='abc123-', min_length=36, max_length=36)
+    ):
+        with MockTransaction:
+            db = db_utils.init_db('sqlite:///:memory:')
+            result = db.vms.insert().execute(uuid=uuid)
+            vm_id = result.inserted_primary_key[0]
+            time = datetime.datetime.today()
+            for i in range(10):
+                db.vm_resource_usage.insert().execute(
+                    vm_id=1,
+                    cpu_mhz=i,
+                    timestamp=time.replace(second=i))
+            state = {
+                'db': db,
+                'time_delta': datetime.timedelta(seconds=5)}
+            expect(cleaner).today(). \
+                and_return(time.replace(second=10)).once()
+            assert db.select_cpu_mhz_for_vm(uuid, 100) == range(10)
+            cleaner.execute({}, state)
+            assert db.select_cpu_mhz_for_vm(uuid, 100) == range(5, 10)
+