diff --git a/debian/control b/debian/control
index 3152930..789b5d1 100644
--- a/debian/control
+++ b/debian/control
@@ -8,7 +8,7 @@ Vcs-Git: https://github.com/ECCC-CCCS/geomet-climate.git
 
 Package: geomet-climate
 Architecture: all
-Depends: ${python3:Depends}, mapserver-bin, python3-all, python3-click, python3-gdal, python3-mappyfile, python3-mapscript, python3-matplotlib, python3-numpy, python3-pyproj, python3-yaml, proj-bin, proj-data, ${misc:Depends}
+Depends: ${python3:Depends}, mapserver-bin, python3-all, python3-click, python3-dateutil, python3-gdal, python3-mappyfile, python3-mapscript, python3-matplotlib, python3-numpy, python3-pyproj, python3-yaml, proj-bin, proj-data, ${misc:Depends}
 Suggests: gdal-bin
 Homepage: https://github.com/ECCC-CCCS/geomet-climate
 Description: MSC GeoMet climate services
diff --git a/geomet_climate/wsgi.py b/geomet_climate/wsgi.py
index d4d6bf1..02173b4 100755
--- a/geomet_climate/wsgi.py
+++ b/geomet_climate/wsgi.py
@@ -112,7 +112,7 @@ def get_custom_service_exception(code, locator, text):
     xsi:schemaLocation="http://www.opengis.net/ogc
     http://schemas.opengis.net/wms/1.3.0/exceptions_1_3_0.xsd">
     <ogc:ServiceException code="{code}" locator="{locator}">{text}</ogc:ServiceException>
-    </ogc:ServiceExceptionReport>'''.format(code=code, locator=locator, text=text), encoding='utf-8')
+    </ogc:ServiceExceptionReport>'''.format(code=code, locator=locator, text=text), encoding='utf-8') # noqa
 
 
 def application(env, start_response):
@@ -215,52 +215,77 @@ def application(env, start_response):
     else:
         LOGGER.debug('Loading mapfile: {}'.format(mapfile_))
         mapfile = mapscript.mapObj(mapfile_)
-        
+        layerobj = mapfile.getLayerByName(layer)
         if request_ == 'GetCapabilities' and lang == 'fr':
             metadata_lang(mapfile, lang)
-            layerobj = mapfile.getLayerByName(layer)
             layerobj.setMetaData('ows_title',
                                  layerobj.getMetaData('ows_title_{}'.format(lang))) # noqa
             layerobj.setMetaData('ows_layer_group',
                                  layerobj.getMetaData('ows_layer_group_{}'.format(lang))) # noqa
 
-        if time_:
+        if time_ and 'ows_timeextent' in layerobj.metadata.keys():
             try:
-                layerobj = mapfile.getLayerByName(layer)
-
+                dates = []
                 timeextent = layerobj.getMetaData('ows_timeextent')
 
                 start_date, end_date, duration = timeextent.split('/')
                 start_date = isoparse(start_date)
                 end_date = isoparse(end_date)
-                time_ = isoparse(time_)
+                time_iso = isoparse(time_)
+
+                end_year_month = (end_date.year - start_date.year)*12
+                end_month = end_date.month - start_date.month
+                end_date = end_year_month + end_month
+
                 if duration == 'P1Y':
-                    dates = [f'{(start_date + relativedelta(months=+i)).year}'
-                        for i in range(0, (end_date.year - start_date.year)*12
-                                        + end_date.month - start_date.month + 1,
-                                        12)]
-                    time_upt = f'{time_.year}'
-                else:
-                    dates = [start_date + relativedelta(months=+i)
-                        for i in range(0, (end_date.year - start_date.year)*12
-                                        + end_date.month - start_date.month + 1,
-                                        1)]
-                    time_upt = f'{time_.year}-{time_.month}'
-
-                print(time_)
-                print(time_upt)
-                print(dates[0])
-                if time_upt in dates:
-                    print(env['QUERY_STRING'])
+                    if time_ != time_iso.strftime('%Y'):
+                        time_error = 'Format de temps invalide, ' \
+                                     'format attendu : YYYY / ' \
+                                     'Invalid time format, ' \
+                                     'expected format: YYYY'
+                        response = get_custom_service_exception('InvalidDimensionValue', # noqa
+                                                                'time',
+                                                                time_error)
+                        start_response('200 OK', [('Content-type',
+                                                   'text/xml')])
+                        return [response]
+
+                    for i in range(0, end_date + 1, 12):
+                        date_ = start_date + relativedelta(months=+i)
+                        dates.append(date_.strftime('%Y'))
+
                 else:
-                    time_error = 'temps en dehors des heures valides / time outside valid hours'
-                    response = get_custom_service_exception('NoMatch', 'time', time_error)
+                    if time_ != time_iso.strftime('%Y-%m'):
+                        time_error = 'Format de temps invalide, ' \
+                                     'format attendu' \
+                                     ' YYYY-MM / Invalid time format, ' \
+                                     'expected format: YYYY-MM'
+                        response = get_custom_service_exception('InvalidDimensionValue', # noqa
+                                                                'time',
+                                                                time_error)
+                        start_response('200 OK', [('Content-type',
+                                                   'text/xml')])
+                        return [response]
+
+                    for i in range(0, end_date + 1, 1):
+                        date_ = start_date + relativedelta(months=+i)
+                        dates.append(date_.strftime('%Y-%m'))
+
+                if time_ not in dates:
+                    time_error = 'Temps en dehors des heures valides /' \
+                                 ' Time outside valid hours'
+                    response = get_custom_service_exception('NoMatch',
+                                                            'time',
+                                                            time_error)
                     start_response('200 OK', [('Content-type', 'text/xml')])
                     return [response]
 
             except ValueError:
-                time_error = 'Format de temps invalide  / time format is invalid'
-                response = get_custom_service_exception('NoMatch', 'time', time_error)
+                time_error = 'Valeur de temps invalide  /' \
+                             ' Time value is invalid'
+                response = get_custom_service_exception('InvalidDimensionValue', # noqa
+                                                        'time',
+                                                        time_error)
                 start_response('200 OK', [('Content-type', 'text/xml')])
                 return [response]
 
diff --git a/requirements.txt b/requirements.txt
index 1d2b9f4..2896d06 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,4 +2,5 @@ click
 mappyfile
 matplotlib
 numpy
+python-dateutil
 pyyaml