diff --git a/framework/test/timestr_test.py b/framework/test/timestr_test.py
new file mode 100644
index 0000000..ad11249
--- /dev/null
+++ b/framework/test/timestr_test.py
@@ -0,0 +1,95 @@
+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""Unittest for timestr module."""
+from __future__ import print_function
+from __future__ import division
+from __future__ import absolute_import
+
+import calendar
+import datetime
+import time
+import unittest
+
+from framework import timestr
+
+
+class TimeStrTest(unittest.TestCase):
+  """Unit tests for timestr routines."""
+
+  def testFormatAbsoluteDate(self):
+    now = datetime.datetime(2008, 1, 1)
+
+    def GetDate(*args):
+      date = datetime.datetime(*args)
+      return timestr.FormatAbsoluteDate(
+          calendar.timegm(date.utctimetuple()), clock=lambda: now)
+
+    self.assertEqual(GetDate(2008, 1, 1), 'Today')
+    self.assertEqual(GetDate(2007, 12, 31), 'Yesterday')
+    self.assertEqual(GetDate(2007, 12, 30), 'Dec 30')
+    self.assertEqual(GetDate(2007, 1, 1), 'Jan 2007')
+    self.assertEqual(GetDate(2007, 1, 2), 'Jan 2007')
+    self.assertEqual(GetDate(2007, 12, 31), 'Yesterday')
+    self.assertEqual(GetDate(2006, 12, 31), 'Dec 2006')
+    self.assertEqual(GetDate(2007, 7, 1), 'Jul 1')
+    self.assertEqual(GetDate(2007, 6, 30), 'Jun 2007')
+    self.assertEqual(GetDate(2008, 1, 3), 'Jan 2008')
+
+    # Leap year fun
+    now = datetime.datetime(2008, 3, 1)
+    self.assertEqual(GetDate(2008, 2, 29), 'Yesterday')
+
+    # Clock skew
+    now = datetime.datetime(2008, 1, 1, 23, 59, 59)
+    self.assertEqual(GetDate(2008, 1, 2), 'Today')
+    now = datetime.datetime(2007, 12, 31, 23, 59, 59)
+    self.assertEqual(GetDate(2008, 1, 1), 'Today')
+    self.assertEqual(GetDate(2008, 1, 2), 'Jan 2008')
+
+  def testFormatRelativeDate(self):
+    now = time.mktime(datetime.datetime(2008, 1, 1).timetuple())
+
+    def TestSecsAgo(secs_ago, expected, expected_days_only):
+      test_time = now - secs_ago
+      actual = timestr.FormatRelativeDate(
+          test_time, clock=lambda: now)
+      self.assertEqual(actual, expected)
+      actual_days_only = timestr.FormatRelativeDate(
+          test_time, clock=lambda: now, days_only=True)
+      self.assertEqual(actual_days_only, expected_days_only)
+
+    TestSecsAgo(10 * 24 * 60 * 60, '', '10 days ago')
+    TestSecsAgo(5 * 24 * 60 * 60 - 1, '4 days ago', '4 days ago')
+    TestSecsAgo(5 * 60 * 60 - 1, '4 hours ago', '')
+    TestSecsAgo(5 * 60 - 1, '4 minutes ago', '')
+    TestSecsAgo(2 * 60 - 1, '1 minute ago', '')
+    TestSecsAgo(60 - 1, 'moments ago', '')
+    TestSecsAgo(0, 'moments ago', '')
+    TestSecsAgo(-10, 'moments ago', '')
+    TestSecsAgo(-100, '', '')
+
+  def testGetHumanScaleDate(self):
+    """Tests GetHumanScaleDate()."""
+    now = time.mktime(datetime.datetime(2008, 4, 10, 20, 50, 30).timetuple())
+
+    def GetDate(*args):
+      date = datetime.datetime(*args)
+      timestamp = time.mktime(date.timetuple())
+      return timestr.GetHumanScaleDate(timestamp, now=now)
+
+    self.assertEqual(GetDate(2008, 4, 10, 15), ('Today', '5 hours ago'))
+    self.assertEqual(GetDate(2008, 4, 10, 19, 55), ('Today', '55 min ago'))
+    self.assertEqual(GetDate(2008, 4, 10, 20, 48, 35), ('Today', '1 min ago'))
+    self.assertEqual(GetDate(2008, 4, 10, 20, 49, 35), ('Today', 'moments ago'))
+    self.assertEqual(GetDate(2008, 4, 10, 20, 50, 55), ('Today', 'moments ago'))
+    self.assertEqual(GetDate(2008, 4, 9, 15), ('Yesterday', '29 hours ago'))
+    self.assertEqual(GetDate(2008, 4, 5, 15), ('Last 7 days', 'Apr 05, 2008'))
+    self.assertEqual(GetDate(2008, 3, 22, 15), ('Last 30 days', 'Mar 22, 2008'))
+    self.assertEqual(
+        GetDate(2008, 1, 2, 15), ('Earlier this year', 'Jan 02, 2008'))
+    self.assertEqual(
+        GetDate(2007, 12, 31, 15), ('Before this year', 'Dec 31, 2007'))
+    self.assertEqual(GetDate(2008, 4, 11, 20, 49, 35), ('Future', 'Later'))