diff --git a/debian/control b/debian/control
index ee11a1c..81a973b 100644
--- a/debian/control
+++ b/debian/control
@@ -20,6 +20,7 @@ Depends: ${python:Depends},
          python-click,
          python-dateutil,
          python-flask,
+         python-tz,
          python-unicodecsv,
          python-yaml,
          ${misc:Depends}
@@ -35,6 +36,7 @@ Depends: ${python3:Depends},
          python3-click,
          python3-dateutil,
          python3-flask,
+         python3-tz,
          python3-unicodecsv,
          python3-yaml,
          ${misc:Depends}
diff --git a/pygeoapi/api.py b/pygeoapi/api.py
index b649e21..7cf5cdd 100644
--- a/pygeoapi/api.py
+++ b/pygeoapi/api.py
@@ -36,6 +36,7 @@ import logging
 import urllib.parse
 
 from dateutil.parser import parse as dateparse
+import pytz
 
 from pygeoapi import __version__
 from pygeoapi.linked_data import (geojson2geojsonld, jsonldify,
@@ -569,14 +570,25 @@ class API(object):
                 'temporal' in self.config['datasets'][dataset]['extents']):
             te = self.config['datasets'][dataset]['extents']['temporal']
 
+            if te['begin'].tzinfo is None:
+                te['begin'] = te['begin'].replace(tzinfo=pytz.UTC)
+            if te['end'].tzinfo is None:
+                te['end'] = te['end'].replace(tzinfo=pytz.UTC)
+
             if '/' in datetime_:  # envelope
                 LOGGER.debug('detected time range')
                 LOGGER.debug('Validating time windows')
                 datetime_begin, datetime_end = datetime_.split('/')
                 if datetime_begin != '..':
                     datetime_begin = dateparse(datetime_begin)
+                    if datetime_begin.tzinfo is None:
+                        datetime_begin = datetime_begin.replace(
+                            tzinfo=pytz.UTC)
+
                 if datetime_end != '..':
                     datetime_end = dateparse(datetime_end)
+                    if datetime_end.tzinfo is None:
+                        datetime_end = datetime_end.replace(tzinfo=pytz.UTC)
 
                 if te['begin'] is not None and datetime_begin != '..':
                     if datetime_begin < te['begin']:
@@ -588,6 +600,9 @@ class API(object):
 
             else:  # time instant
                 datetime__ = dateparse(datetime_)
+                if datetime__ != '..':
+                    if datetime__.tzinfo is None:
+                        datetime__ = datetime__.replace(tzinfo=pytz.UTC)
                 LOGGER.debug('detected time instant')
                 if te['begin'] is not None and datetime__ != '..':
                     if datetime__ < te['begin']:
diff --git a/requirements.txt b/requirements.txt
index 4e39b94..9e247b7 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,6 @@
 click
-python-dateutil
 Flask
+python-dateutil
+pytz
 PyYAML
 unicodecsv
diff --git a/tests/test_api.py b/tests/test_api.py
index 1184472..ad4a818 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -215,7 +215,9 @@ def test_describe_collections(config, api_):
             'crs': 'http://www.opengis.net/def/crs/OGC/1.3/CRS84'
         },
         'temporal': {
-            'interval': [['2000-10-30T18:24:39', '2007-10-30T08:57:29']],
+            'interval': [
+                ['2000-10-30T18:24:39+00:00', '2007-10-30T08:57:29+00:00']
+            ],
             'trs': 'http://www.opengis.net/def/uom/ISO-8601/0/Gregorian'
         }
     }
@@ -254,7 +256,7 @@ def test_describe_collections_json_ld(config, api_):
 
     assert 'http://schema.org/temporalCoverage' in dataset
     assert dataset['http://schema.org/temporalCoverage'][0][
-        '@value'] == '2000-10-30T18:24:39/2007-10-30T08:57:29'
+        '@value'] == '2000-10-30T18:24:39+00:00/2007-10-30T08:57:29+00:00'
 
 
 def test_get_collection_items(config, api_):