diff --git a/locking/models.py b/locking/models.py
index d43e601..ced1853 100644
--- a/locking/models.py
+++ b/locking/models.py
@@ -1,6 +1,6 @@
 # encoding: utf-8
 
-from datetime import datetime
+from datetime import datetime, timedelta
 
 from django.db import models
 from django.conf import settings
@@ -79,7 +79,7 @@ def is_locked(self):
 		Works by calculating if the last lock (self.locked_at) has timed out or not.
 		"""
 		if isinstance(self.locked_at, datetime):
-			if (datetime.today() - self.locked_at).seconds < settings.LOCKING['time_until_expiration']:
+			if (datetime.today() - self.locked_at) < timedelta(seconds=settings.LOCKING['time_until_expiration']):
 				return True
 			else:
 				return False
@@ -97,7 +97,8 @@ def lock_seconds_remaining(self):
 		If you want to extend a lock beyond its current expiry date, initiate a new
 		lock using the ``lock_for`` method.
 		"""
-		return settings.LOCKING['time_until_expiration'] - (datetime.today() - self.locked_at).seconds
+		diff = timedelta(settings.LOCKING['time_until_expiration']) - (datetime.today() - self.locked_at)
+		return (diff.days * 24 * 60 * 60) + diff.seconds
 	
 	def lock_for(self, user, hard_lock=True):
 		"""
diff --git a/locking/tests/tests.py b/locking/tests/tests.py
index 6fe3e13..b8a494f 100644
--- a/locking/tests/tests.py
+++ b/locking/tests/tests.py
@@ -71,7 +71,39 @@ def test_lock_expiration(self):
         self.assertTrue(self.story.is_locked)
         self.story._locked_at = datetime.today() - timedelta(minutes=LOCK_TIMEOUT+1)
         self.assertFalse(self.story.is_locked)
-    
+
+    def test_lock_expiration_day(self):
+        self.story.lock_for(self.user)
+        self.assertTrue(self.story.is_locked)
+        self.story._locked_at = datetime.today() - timedelta(days=1, seconds=1)
+        self.assertFalse(self.story.is_locked)
+
+    def test_lock_seconds_remaining(self):
+        self.story.lock_for(self.user)
+        expected = LOCK_TIMEOUT
+        self.assertTrue(self.story.lock_seconds_remaining <= expected + 1 and
+                        self.story.lock_seconds_remaining >= expected - 1,
+                        "%d not close to %d" % (
+                            self.story.lock_seconds_remaining, expected))
+
+    def test_lock_seconds_remaining_half_timeout(self):
+        self.story.lock_for(self.user)
+        self.story._locked_at -= timedelta(seconds=(LOCK_TIMEOUT / 2))
+        expected = LOCK_TIMEOUT / 2
+        self.assertTrue(self.story.lock_seconds_remaining <= expected + 1 and
+                        self.story.lock_seconds_remaining >= expected - 1,
+                        "%d not close to %d" % (
+                            self.story.lock_seconds_remaining, expected))
+
+    def test_lock_seconds_remaining_day(self):
+        self.story.lock_for(self.user)
+        self.story._locked_at -= timedelta(days=1)
+        expected = LOCK_TIMEOUT - (24 * 60 * 60)
+        self.assertTrue(self.story.lock_seconds_remaining <= expected + 1 and
+                        self.story.lock_seconds_remaining >= expected - 1,
+                        "%d not close to %d" % (
+                            self.story.lock_seconds_remaining, expected))
+
     def test_lock_applies_to(self):
         self.story.lock_for(self.alt_user)
         applies = self.story.lock_applies_to(self.user)