diff --git a/test/datetime-negative.t b/test/datetime-negative.t
new file mode 100755
index 000000000..9614e891b
--- /dev/null
+++ b/test/datetime-negative.t
@@ -0,0 +1,137 @@
+#!/usr/bin/env python2.7
+# -*- coding: utf-8 -*-
+################################################################################
+##
+## Copyright 2006 - 2015, Paul Beckingham, Federico Hernandez.
+##
+## Permission is hereby granted, free of charge, to any person obtaining a copy
+## of this software and associated documentation files (the "Software"), to deal
+## in the Software without restriction, including without limitation the rights
+## to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+## copies of the Software, and to permit persons to whom the Software is
+## furnished to do so, subject to the following conditions:
+##
+## The above copyright notice and this permission notice shall be included
+## in all copies or substantial portions of the Software.
+##
+## THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+## OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+## FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+## THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+## LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+## OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+## SOFTWARE.
+##
+## http://www.opensource.org/licenses/mit-license.php
+##
+################################################################################
+
+import json
+import sys
+import os
+import unittest
+
+# Ensure python finds the local simpletap module
+sys.path.append(os.path.dirname(os.path.abspath(__file__)))
+
+from basetest import Task, TestCase
+
+class TestIncorrectDate(TestCase):
+    """
+    This test case makes sure various formats
+    of incorrect datetimes do not get interpreted
+    as valid timetamps. Covers TW-1499.
+    """
+
+    def setUp(self):
+        self.t = Task()
+
+    def assertInvalidDatetimeFormat(self, value):
+        self.t.runError(('add', 'due:%s' % value, 'test1'))
+        self.t.runError(('add', 'scheduled:%s' % value, 'test2'))
+        self.t.runError(('add', 'wait:%s' % value, 'test3'))
+        self.t.runError(('add', 'until:%s' % value, 'test4'))
+
+    def test_set_incorrect_datetime_randomstring(self):
+        self.assertInvalidDatetimeFormat('random')
+
+    def test_set_incorrect_datetime_negative_in_YYYY_MM_DD(self):
+        self.assertInvalidDatetimeFormat('-2014-07-07')
+
+    def test_set_incorrect_datetime_missing_day_in_YYYY_MM_DD(self):
+        self.assertInvalidDatetimeFormat('2014-07-')
+
+    def test_set_incorrect_datetime_month_zero_in_YYYY_MM_DD(self):
+        self.assertInvalidDatetimeFormat('2014-0-12')
+
+    def test_set_incorrect_datetime_invalid_characters_in_YYYY_MM_DD(self):
+        self.assertInvalidDatetimeFormat('abcd-ab-ab')
+
+    def test_set_incorrect_datetime_day_as_zeros_in_YYYY_DDD(self):
+        self.assertInvalidDatetimeFormat('2014-000')
+
+    def test_set_incorrect_datetime_overlap_day_in_nonoverlap_year_in_YYYY_DDD(self):
+        self.assertInvalidDatetimeFormat('2014-366')
+
+    def test_set_incorrect_datetime_medium_overlap_day_in_YYYY_DDD(self):
+        self.assertInvalidDatetimeFormat('2014-999')
+
+    def test_set_incorrect_datetime_huge_overlap_day_in_YYYY_DDD(self):
+        self.assertInvalidDatetimeFormat('2014-999999999')
+
+    def test_set_incorrect_datetime_week_with_the_number_zero_in_YYYY_Www(self):
+        self.assertInvalidDatetimeFormat('2014-W00')
+
+    def test_set_incorrect_datetime_overflow_in_week_in_YYYY_Www(self):
+        self.assertInvalidDatetimeFormat('2014-W54')
+
+    def test_set_incorrect_datetime_day_zero_in_YYYY_WwwD(self):
+        self.assertInvalidDatetimeFormat('2014-W240')
+
+    def test_set_incorrect_datetime_day_eight_in_YYYY_WwwD(self):
+        self.assertInvalidDatetimeFormat('2014-W248')
+
+    def test_set_incorrect_datetime_day_two_hundred_in_YYYY_WwwD(self):
+        self.assertInvalidDatetimeFormat('2014-W24200')
+
+    def test_set_incorrect_datetime_week_with_the_number_zero_in_YYYYWww(self):
+        self.assertInvalidDatetimeFormat('2014W00')
+
+    def test_set_incorrect_datetime_overflow_in_week_in_YYYYWww(self):
+        self.assertInvalidDatetimeFormat('2014W54')
+
+    def test_set_incorrect_datetime_week_zero_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W001')
+
+    def test_set_incorrect_datetime_fifth_day_of_week_zero_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W005')
+
+    def test_set_incorrect_datetime_overflow_week_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W541')
+
+    def test_set_incorrect_datetime_huge_overflow_week_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W991')
+
+    def test_set_incorrect_datetime_day_zero_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W240')
+
+    def test_set_incorrect_datetime_day_eight_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W248')
+
+    def test_set_incorrect_datetime_day_two_hundred_in_YYYYWwwD(self):
+        self.assertInvalidDatetimeFormat('2014W24200')
+
+    def test_set_incorrect_datetime_month_zero_in_YYYY_MM(self):
+        self.assertInvalidDatetimeFormat('2014-00')
+
+    def test_set_incorrect_datetime_overflow_month_in_YYYY_MM(self):
+        self.assertInvalidDatetimeFormat('2014-13')
+
+    def test_set_incorrect_datetime_huge_overflow_month_in_YYYY_MM(self):
+        self.assertInvalidDatetimeFormat('2014-99')
+
+if __name__ == "__main__":
+    from simpletap import TAPTestRunner
+    unittest.main(testRunner=TAPTestRunner())
+
+# vim: ai sts=4 et sw=4