diff --git a/doc/manpages/swift.1 b/doc/manpages/swift.1
index bbf5280..1f288d6 100644
--- a/doc/manpages/swift.1
+++ b/doc/manpages/swift.1
@@ -130,14 +130,33 @@ programs, such as jq.
          capabilities \-\-json
 .RE
 
-\fBtempurl\fR [\fIcommand-option\fR] \fImethod\fR \fIseconds\fR \fIpath\fR \fIkey\fR
+\fBtempurl\fR [\fIcommand-option\fR] \fImethod\fR \fItime\fR \fIpath\fR \fIkey\fR
 .RS 4
 Generates a temporary URL allowing unauthenticated access to the Swift object
-at the given path, using the given HTTP method, for the given number of
-seconds, using the given TempURL key. With the optional \-\-prefix\-based option a
-prefix-based URL is generated. If optional \-\-absolute argument is
-provided, seconds is instead interpreted as a Unix timestamp at which the URL
-should expire. \fBExample\fR: tempurl GET $(date \-d "Jan 1 2016" +%s)
+at the given path, using the given HTTP method, for the given time,
+using the given TempURL key.
+
+The time can be specified either as an integer
+denoting the amount of seconds the temporary URL is valid, or as an ISO 8601
+timestamp in one of following formats:  Complete date: YYYY\-MM\-DD (eg 1997\-07\-16),
+complete date plus hours, minutes and seconds: YYYY\-MM\-DDThh:mm:ss
+(eg 1997\-07\-16T19:20:30) or complete date plus hours, minutes and seconds with
+UTC designator: YYYY\-MM\-DDThh:mm:ssZ (eg 1997\-07\-16T19:20:30Z). Be aware that
+if you do not use the latter format, the timestamp is generated using your locale
+timezone. If the first format is used, the time part used will equal to 00:00:00.
+
+With the \-\-prefix\-based option a
+prefix-based URL is generated.
+
+The option \-\-iso8601 provides ISO 8601 UTC timestamps
+instead of Unix timestamps inside the generated URL.
+
+If optional \-\-absolute argument is
+provided and the time argument is specified in seconds, the seconds are
+interpreted as a Unix timestamp at which the URL
+should expire.
+
+\fBExample\fR: tempurl GET $(date \-d "Jan 1 2016" +%s)
 /v1/AUTH_foo/bar_container/quux.md my_secret_tempurl_key \-\-absolute
 
 .RE
diff --git a/doc/source/cli.rst b/doc/source/cli.rst
index b107448..8d80d1b 100644
--- a/doc/source/cli.rst
+++ b/doc/source/cli.rst
@@ -228,18 +228,39 @@ Capabilities
 Tempurl
 -------
 
-    ``tempurl [command-options] [method] [seconds] [path] [key]``
+    ``tempurl [command-options] [method] [time] [path] [key]``
 
        Generates a temporary URL for a Swift object. ``method`` option sets an HTTP method to
-       allow for this temporary URL that is usually 'GET' or 'PUT'. ``seconds`` option sets
-       the amount of time in seconds the temporary URL will be valid for; or, if ``--absolute``
-       is passed, the Unix timestamp when the temporary URL will expire. ``path`` option sets
-       the full path to the Swift object. Example: ``/v1/AUTH_account/c/o``. ``key`` option is
+       allow for this temporary URL that is usually ``GET` or ``PUT``. ``time`` option sets
+       the amount of time the temporary URL will be valid for.
+       ``time`` can be specified as an integer, denoting the number of seconds
+       from now on until the URL shall be valid; or, if ``--absolute``
+       is passed, the Unix timestamp when the temporary URL will expire.
+       But beyond that, ``time`` can also be specified as an ISO 8601 timestamp
+       in one of following formats:
+
+        i) Complete date: YYYY-MM-DD (eg 1997-07-16)
+
+        ii) Complete date plus hours, minutes and seconds:
+           YYYY-MM-DDThh:mm:ss
+         (eg 1997-07-16T19:20:30)
+
+        iii) Complete date plus hours, minutes and seconds with UTC designator:
+            YYYY-MM-DDThh:mm:ssZ
+         (eg 1997-07-16T19:20:30Z)
+
+       Please be aware that if you don't provide the UTC designator (i.e., Z)
+       the timestamp is generated using your local timezone. If only a date is
+       specified, the time part used will equal to ``00:00:00``.
+
+       ``path`` option sets the full path to the Swift object.
+       Example: ``/v1/AUTH_account/c/o``. ``key`` option is
        the secret temporary URL key set on the Swift cluster. To set a key, run
        ``swift post -m "Temp-URL-Key: <your secret key>"``. To generate a prefix-based temporary
        URL use the ``--prefix-based`` option. This URL will contain the path to the prefix. Do not
        forget to append the desired objectname at the end of the path portion (and before the
-       query portion) before sharing the URL.
+       query portion) before sharing the URL. It is possible to use ISO 8601 UTC timestamps within the
+       URL by using the ``--iso8601`` option.
 
 Auth
 ----
diff --git a/swiftclient/shell.py b/swiftclient/shell.py
index 4a8a356..841ed6e 100755
--- a/swiftclient/shell.py
+++ b/swiftclient/shell.py
@@ -1224,8 +1224,8 @@ def st_auth(parser, args, thread_manager):
         print('export OS_AUTH_TOKEN=%s' % sh_quote(token))
 
 
-st_tempurl_options = '''[--absolute] [--prefix-based]
-                     <method> <seconds> <path> <key>'''
+st_tempurl_options = '''[--absolute] [--prefix-based] [--iso8601]
+                     <method> <time> <path> <key>'''
 
 
 st_tempurl_help = '''
@@ -1234,9 +1234,35 @@ Generates a temporary URL for a Swift object.
 Positional arguments:
   <method>              An HTTP method to allow for this temporary URL.
                         Usually 'GET' or 'PUT'.
-  <seconds>             The amount of time in seconds the temporary URL will be
-                        valid for; or, if --absolute is passed, the Unix
-                        timestamp when the temporary URL will expire.
+  <time>                The amount of time the temporary URL will be
+                        valid. The time can be specified in two ways:
+                        an integer representing the time in seconds or an
+                        ISO 8601 timestamp in a specific format.
+                        If --absolute is passed and time
+                        is an integer, the seconds are intepreted as the Unix
+                        timestamp when the temporary URL will expire. The ISO
+                        8601 timestamp can be specified in one of following
+                        formats:
+
+                        i) Complete date: YYYY-MM-DD (eg 1997-07-16)
+
+                        ii) Complete date plus hours, minutes and seconds:
+
+                            YYYY-MM-DDThh:mm:ss
+
+                           (eg 1997-07-16T19:20:30)
+
+                        iii) Complete date plus hours, minutes and seconds with
+                             UTC designator:
+
+                             YYYY-MM-DDThh:mm:ssZ
+
+                             (eg 1997-07-16T19:20:30Z)
+
+                        Please be aware that if you don't provide the UTC
+                        designator (i.e., Z) the timestamp is generated using
+                        your local timezone. If only a date is specified,
+                        the time part used will equal to 00:00:00.
   <path>                The full path or storage URL to the Swift object.
                         Example: /v1/AUTH_account/c/o
                         or: http://saio:8080/v1/AUTH_account/c/o
@@ -1245,10 +1271,14 @@ Positional arguments:
                         "Temp-URL-Key:b3968d0207b54ece87cccc06515a89d4"\'
 
 Optional arguments:
-  --absolute            Interpret the <seconds> positional argument as a Unix
+  --absolute            Interpret the <time> positional argument as a Unix
                         timestamp rather than a number of seconds in the
-                        future.
-  --prefix-based	If present, a prefix-based tempURL will be generated.
+                        future. If an ISO 8601 timestamp is passed for <time>,
+                        this argument is ignored.
+  --prefix-based        If present, a prefix-based temporary URL will be
+                        generated.
+  --iso8601             If present, the generated temporary URL will contain an
+                        ISO 8601 UTC timestamp instead of a Unix timestamp.
 '''.strip('\n')
 
 
@@ -1256,14 +1286,21 @@ def st_tempurl(parser, args, thread_manager):
     parser.add_argument(
         '--absolute', action='store_true',
         dest='absolute_expiry', default=False,
-        help=("If present, seconds argument will be interpreted as a Unix "
-              "timestamp representing when the tempURL should expire, rather "
-              "than an offset from the current time"),
+        help=("If present, and time argument is an integer, "
+              "time argument will be interpreted as a Unix "
+              "timestamp representing when the temporary URL should expire, "
+              "rather than an offset from the current time."),
     )
     parser.add_argument(
         '--prefix-based', action='store_true',
         default=False,
-        help=("If present, a prefix-based tempURL will be generated."),
+        help=("If present, a prefix-based temporary URL will be generated."),
+    )
+    parser.add_argument(
+        '--iso8601', action='store_true',
+        default=False,
+        help=("If present, the temporary URL will contain an ISO 8601 UTC "
+              "timestamp instead of a Unix timestamp."),
     )
 
     (options, args) = parse_args(parser, args)
@@ -1272,7 +1309,7 @@ def st_tempurl(parser, args, thread_manager):
         thread_manager.error('Usage: %s tempurl %s\n%s', BASENAME,
                              st_tempurl_options, st_tempurl_help)
         return
-    method, seconds, path, key = args[:4]
+    method, timestamp, path, key = args[:4]
 
     parsed = urlparse(path)
 
@@ -1281,9 +1318,10 @@ def st_tempurl(parser, args, thread_manager):
                                  'tempurl specified, possibly an error' %
                                  method.upper())
     try:
-        path = generate_temp_url(parsed.path, seconds, key, method,
+        path = generate_temp_url(parsed.path, timestamp, key, method,
                                  absolute=options['absolute_expiry'],
-                                 prefix=options['prefix_based'],)
+                                 iso8601=options['iso8601'],
+                                 prefix=options['prefix_based'])
     except ValueError as err:
         thread_manager.error(err)
         return
diff --git a/swiftclient/utils.py b/swiftclient/utils.py
index 08cd7b2..8afcde9 100644
--- a/swiftclient/utils.py
+++ b/swiftclient/utils.py
@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Miscellaneous utility functions for use with Swift."""
+from calendar import timegm
 import collections
 import gzip
 import hashlib
@@ -25,6 +26,10 @@ import traceback
 
 TRUE_VALUES = set(('true', '1', 'yes', 'on', 't', 'y'))
 EMPTY_ETAG = 'd41d8cd98f00b204e9800998ecf8427e'
+EXPIRES_ISO8601_FORMAT = '%Y-%m-%dT%H:%M:%SZ'
+SHORT_EXPIRES_ISO8601_FORMAT = '%Y-%m-%d'
+TIME_ERRMSG = ('time must either be a whole number or in specific '
+               'ISO 8601 format.')
 
 
 def config_true_value(value):
@@ -64,39 +69,65 @@ def prt_bytes(num_bytes, human_flag):
 
 
 def generate_temp_url(path, seconds, key, method, absolute=False,
-                      prefix=False):
+                      prefix=False, iso8601=False):
     """Generates a temporary URL that gives unauthenticated access to the
     Swift object.
 
     :param path: The full path to the Swift object or prefix if
          a prefix-based temporary URL should be generated. Example:
         /v1/AUTH_account/c/o or /v1/AUTH_account/c/prefix.
-    :param seconds: If absolute is False then this specifies the amount of time
-        in seconds for which the temporary URL will be valid. If absolute is
-        True then this specifies an absolute time at which the temporary URL
-        will expire.
+    :param seconds: time in seconds or ISO 8601 timestamp.
+        If absolute is False and this is the string representation of an
+        integer, then this specifies the amount of time in seconds for which
+        the temporary URL will be valid.
+        If absolute is True then this specifies an absolute time at which the
+        temporary URL will expire.
     :param key: The secret temporary URL key set on the Swift
         cluster. To set a key, run 'swift post -m
         "Temp-URL-Key: <substitute tempurl key here>"'
     :param method: A HTTP method, typically either GET or PUT, to allow
         for this temporary URL.
-    :param absolute: if True then the seconds parameter is interpreted as an
-        absolute Unix time, otherwise seconds is interpreted as a relative time
-        offset from current time.
+    :param absolute: if True then the seconds parameter is interpreted as a
+        Unix timestamp, if seconds represents an integer.
     :param prefix: if True then a prefix-based temporary URL will be generated.
-    :raises ValueError: if seconds is not a whole number or path is not to
-        an object.
+    :param iso8601: if True, a URL containing an ISO 8601 UTC timestamp
+        instead of a UNIX timestamp will be created.
+    :raises ValueError: if timestamp or path is not in valid format.
     :return: the path portion of a temporary URL
     """
     try:
-        seconds = float(seconds)
-        if not seconds.is_integer():
-            raise ValueError()
-        seconds = int(seconds)
-        if seconds < 0:
-            raise ValueError()
+        try:
+            timestamp = float(seconds)
+        except ValueError:
+            formats = (
+                EXPIRES_ISO8601_FORMAT,
+                EXPIRES_ISO8601_FORMAT[:-1],
+                SHORT_EXPIRES_ISO8601_FORMAT)
+            for f in formats:
+                try:
+                    t = time.strptime(seconds, f)
+                except ValueError:
+                    t = None
+                else:
+                    if f == EXPIRES_ISO8601_FORMAT:
+                        timestamp = timegm(t)
+                    else:
+                        # Use local time if UTC designator is missing.
+                        timestamp = int(time.mktime(t))
+
+                    absolute = True
+                    break
+
+            if t is None:
+                raise ValueError()
+        else:
+            if not timestamp.is_integer():
+                raise ValueError()
+            timestamp = int(timestamp)
+            if timestamp < 0:
+                raise ValueError()
     except ValueError:
-        raise ValueError('seconds must be a whole number')
+        raise ValueError(TIME_ERRMSG)
 
     if isinstance(path, six.binary_type):
         try:
@@ -121,9 +152,9 @@ def generate_temp_url(path, seconds, key, method, absolute=False,
                        'possibly an error', method.upper())
 
     if not absolute:
-        expiration = int(time.time() + seconds)
+        expiration = int(time.time() + timestamp)
     else:
-        expiration = seconds
+        expiration = timestamp
     hmac_body = u'\n'.join([method.upper(), str(expiration),
                             ('prefix:' if prefix else '') + path_for_body])
 
@@ -132,6 +163,10 @@ def generate_temp_url(path, seconds, key, method, absolute=False,
         key = key.encode('utf-8')
     sig = hmac.new(key, hmac_body.encode('utf-8'), hashlib.sha1).hexdigest()
 
+    if iso8601:
+        expiration = time.strftime(
+            EXPIRES_ISO8601_FORMAT, time.gmtime(expiration))
+
     temp_url = u'{path}?temp_url_sig={sig}&temp_url_expires={exp}'.format(
         path=path_for_body, sig=sig, exp=expiration)
     if prefix:
diff --git a/tests/unit/test_shell.py b/tests/unit/test_shell.py
index f7e9c1a..2fe0139 100644
--- a/tests/unit/test_shell.py
+++ b/tests/unit/test_shell.py
@@ -23,6 +23,7 @@ import os
 import tempfile
 import unittest
 import textwrap
+from time import localtime, mktime, strftime, strptime
 
 from requests.packages.urllib3.exceptions import InsecureRequestWarning
 import six
@@ -36,7 +37,9 @@ from os.path import basename, dirname
 from .utils import (
     CaptureOutput, fake_get_auth_keystone, _make_fake_import_keystone_client,
     FakeKeystone, StubResponse, MockHttpTest)
-from swiftclient.utils import EMPTY_ETAG
+from swiftclient.utils import (
+    EMPTY_ETAG, EXPIRES_ISO8601_FORMAT,
+    SHORT_EXPIRES_ISO8601_FORMAT, TIME_ERRMSG)
 
 
 if six.PY2:
@@ -1550,7 +1553,7 @@ class TestShell(unittest.TestCase):
         swiftclient.shell.main(argv)
         temp_url.assert_called_with(
             '/v1/AUTH_account/c/o', "60", 'secret_key', 'GET', absolute=False,
-            prefix=False)
+            iso8601=False, prefix=False)
 
     @mock.patch('swiftclient.shell.generate_temp_url', return_value='')
     def test_temp_url_prefix_based(self, temp_url):
@@ -1559,7 +1562,28 @@ class TestShell(unittest.TestCase):
         swiftclient.shell.main(argv)
         temp_url.assert_called_with(
             '/v1/AUTH_account/c/', "60", 'secret_key', 'GET', absolute=False,
-            prefix=True)
+            iso8601=False, prefix=True)
+
+    @mock.patch('swiftclient.shell.generate_temp_url', return_value='')
+    def test_temp_url_iso8601_in(self, temp_url):
+        dates = ('1970-01-01T00:01:00Z', '1970-01-01T00:01:00',
+                 '1970-01-01')
+        for d in dates:
+            argv = ["", "tempurl", "GET", d, "/v1/AUTH_account/c/",
+                    "secret_key"]
+            swiftclient.shell.main(argv)
+            temp_url.assert_called_with(
+                '/v1/AUTH_account/c/', d, 'secret_key', 'GET', absolute=False,
+                iso8601=False, prefix=False)
+
+    @mock.patch('swiftclient.shell.generate_temp_url', return_value='')
+    def test_temp_url_iso8601_out(self, temp_url):
+        argv = ["", "tempurl", "GET", "60", "/v1/AUTH_account/c/",
+                "secret_key", "--iso8601"]
+        swiftclient.shell.main(argv)
+        temp_url.assert_called_with(
+            '/v1/AUTH_account/c/', "60", 'secret_key', 'GET', absolute=False,
+            iso8601=True, prefix=False)
 
     @mock.patch('swiftclient.shell.generate_temp_url', return_value='')
     def test_absolute_expiry_temp_url(self, temp_url):
@@ -1568,7 +1592,7 @@ class TestShell(unittest.TestCase):
         swiftclient.shell.main(argv)
         temp_url.assert_called_with(
             '/v1/AUTH_account/c/o', "60", 'secret_key', 'GET', absolute=True,
-            prefix=False)
+            iso8601=False, prefix=False)
 
     def test_temp_url_output(self):
         argv = ["", "tempurl", "GET", "60", "/v1/a/c/o",
@@ -1595,6 +1619,42 @@ class TestShell(unittest.TestCase):
                     "&temp_url_prefix=\n" % sig)
         self.assertEqual(expected, output.out)
 
+        argv = ["", "tempurl", "GET", "60", "/v1/a/c/",
+                "secret_key", "--absolute", "--prefix", '--iso8601']
+        with CaptureOutput(suppress_systemexit=True) as output:
+            swiftclient.shell.main(argv)
+        sig = '00008c4be1573ba74fc2ab9bce02e3a93d04b349'
+        expires = '1970-01-01T00:01:00Z'
+        expected = ("/v1/a/c/?temp_url_sig=%s&temp_url_expires=%s"
+                    "&temp_url_prefix=\n" % (sig, expires))
+        self.assertEqual(expected, output.out)
+
+        dates = ("1970-01-01T00:01:00Z",
+                 strftime(EXPIRES_ISO8601_FORMAT[:-1], localtime(60)))
+        for d in dates:
+            argv = ["", "tempurl", "GET", d, "/v1/a/c/o",
+                    "secret_key"]
+            with CaptureOutput(suppress_systemexit=True) as output:
+                swiftclient.shell.main(argv)
+            sig = "63bc77a473a1c2ce956548cacf916f292eb9eac3"
+            expected = "/v1/a/c/o?temp_url_sig=%s&temp_url_expires=60\n" % sig
+            self.assertEqual(expected, output.out)
+
+        ts = str(int(
+            mktime(strptime('2005-05-01', SHORT_EXPIRES_ISO8601_FORMAT))))
+
+        argv = ["", "tempurl", "GET", ts, "/v1/a/c/",
+                "secret_key", "--absolute"]
+        with CaptureOutput(suppress_systemexit=True) as output:
+            swiftclient.shell.main(argv)
+            expected = output.out
+
+        argv = ["", "tempurl", "GET", '2005-05-01', "/v1/a/c/",
+                "secret_key", "--absolute"]
+        with CaptureOutput(suppress_systemexit=True) as output:
+            swiftclient.shell.main(argv)
+            self.assertEqual(expected, output.out)
+
     def test_temp_url_error_output(self):
         expected = 'path must be full path to an object e.g. /v1/a/c/o\n'
         for bad_path in ('/v1/a/c', 'v1/a/c/o', '/v1/a/c/', '/v1/a//o',
@@ -1614,7 +1674,17 @@ class TestShell(unittest.TestCase):
                 swiftclient.shell.main(argv)
         self.assertEqual(expected, output.err,
                          'Expected %r but got %r for path %r' %
-                         (expected, output.err, bad_path))
+                         (expected, output.err, '/v1/a/c'))
+
+        expected = TIME_ERRMSG + '\n'
+        for bad_time in ('not_an_int', '-1', '2015-05', '2015-05-01T01:00'):
+            argv = ["", "tempurl", "GET", bad_time, '/v1/a/c/o',
+                        "secret_key", "--absolute"]
+            with CaptureOutput(suppress_systemexit=True) as output:
+                    swiftclient.shell.main(argv)
+            self.assertEqual(expected, output.err,
+                             'Expected %r but got %r for time %r' %
+                             (expected, output.err, bad_time))
 
     @mock.patch('swiftclient.service.Connection')
     def test_capabilities(self, connection):
diff --git a/tests/unit/test_utils.py b/tests/unit/test_utils.py
index c5961e8..adead00 100644
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -18,6 +18,7 @@ import unittest
 import mock
 import six
 import tempfile
+from time import gmtime, localtime, mktime, strftime, strptime
 from hashlib import md5, sha1
 
 from swiftclient import utils as u
@@ -150,6 +151,67 @@ class TestTempURL(unittest.TestCase):
         ])
         self.assertIsInstance(url, type(self.url))
 
+    @mock.patch('hmac.HMAC')
+    def test_generate_temp_url_iso8601_argument(self, hmac_mock):
+        hmac_mock().hexdigest.return_value = 'temp_url_signature'
+        url = u.generate_temp_url(self.url, '2014-05-13T17:53:20Z',
+                                  self.key, self.method)
+        self.assertEqual(url, self.expected_url)
+
+        # Don't care about absolute arg.
+        url = u.generate_temp_url(self.url, '2014-05-13T17:53:20Z',
+                                  self.key, self.method, absolute=True)
+        self.assertEqual(url, self.expected_url)
+
+        lt = localtime()
+        expires = strftime(u.EXPIRES_ISO8601_FORMAT[:-1], lt)
+
+        if not isinstance(self.expected_url, six.string_types):
+            expected_url = self.expected_url.replace(
+                b'1400003600', bytes(str(int(mktime(lt))), encoding='ascii'))
+        else:
+            expected_url = self.expected_url.replace(
+                '1400003600', str(int(mktime(lt))))
+        url = u.generate_temp_url(self.url, expires,
+                                  self.key, self.method)
+        self.assertEqual(url, expected_url)
+
+        expires = strftime(u.SHORT_EXPIRES_ISO8601_FORMAT, lt)
+        lt = strptime(expires, u.SHORT_EXPIRES_ISO8601_FORMAT)
+
+        if not isinstance(self.expected_url, six.string_types):
+            expected_url = self.expected_url.replace(
+                b'1400003600', bytes(str(int(mktime(lt))), encoding='ascii'))
+        else:
+            expected_url = self.expected_url.replace(
+                '1400003600', str(int(mktime(lt))))
+        url = u.generate_temp_url(self.url, expires,
+                                  self.key, self.method)
+        self.assertEqual(url, expected_url)
+
+    @mock.patch('hmac.HMAC')
+    @mock.patch('time.time', return_value=1400000000)
+    def test_generate_temp_url_iso8601_output(self, time_mock, hmac_mock):
+        hmac_mock().hexdigest.return_value = 'temp_url_signature'
+        url = u.generate_temp_url(self.url, self.seconds,
+                                  self.key, self.method,
+                                  iso8601=True)
+        key = self.key
+        if not isinstance(key, six.binary_type):
+            key = key.encode('utf-8')
+
+        expires = strftime(u.EXPIRES_ISO8601_FORMAT, gmtime(1400003600))
+        if not isinstance(self.url, six.string_types):
+            self.assertTrue(url.endswith(bytes(expires, 'utf-8')))
+        else:
+            self.assertTrue(url.endswith(expires))
+        self.assertEqual(hmac_mock.mock_calls, [
+            mock.call(),
+            mock.call(key, self.expected_body, sha1),
+            mock.call().hexdigest(),
+        ])
+        self.assertIsInstance(url, type(self.url))
+
     @mock.patch('hmac.HMAC')
     @mock.patch('time.time', return_value=1400000000)
     def test_generate_temp_url_prefix(self, time_mock, hmac_mock):
@@ -198,31 +260,34 @@ class TestTempURL(unittest.TestCase):
                                   absolute=True)
         self.assertEqual(url, expected_url)
 
-    def test_generate_temp_url_bad_seconds(self):
+    def test_generate_temp_url_bad_time(self):
         with self.assertRaises(ValueError) as exc_manager:
             u.generate_temp_url(self.url, 'not_an_int', self.key, self.method)
-        self.assertEqual(exc_manager.exception.args[0],
-                         'seconds must be a whole number')
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
 
         with self.assertRaises(ValueError) as exc_manager:
             u.generate_temp_url(self.url, -1, self.key, self.method)
-        self.assertEqual(exc_manager.exception.args[0],
-                         'seconds must be a whole number')
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
 
         with self.assertRaises(ValueError) as exc_manager:
             u.generate_temp_url(self.url, 1.1, self.key, self.method)
-        self.assertEqual(exc_manager.exception.args[0],
-                         'seconds must be a whole number')
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
 
         with self.assertRaises(ValueError) as exc_manager:
             u.generate_temp_url(self.url, '-1', self.key, self.method)
-        self.assertEqual(exc_manager.exception.args[0],
-                         'seconds must be a whole number')
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
 
         with self.assertRaises(ValueError) as exc_manager:
             u.generate_temp_url(self.url, '1.1', self.key, self.method)
-        self.assertEqual(exc_manager.exception.args[0],
-                         'seconds must be a whole number')
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
+        with self.assertRaises(ValueError) as exc_manager:
+            u.generate_temp_url(self.url, '2015-05', self.key, self.method)
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
+
+        with self.assertRaises(ValueError) as exc_manager:
+            u.generate_temp_url(
+                self.url, '2015-05-01T01:00', self.key, self.method)
+        self.assertEqual(exc_manager.exception.args[0], u.TIME_ERRMSG)
 
     def test_generate_temp_url_bad_path(self):
         with self.assertRaises(ValueError) as exc_manager: