diff --git a/app/main/views/new_password.py b/app/main/views/new_password.py
index ed45c3c1d..7b3c701f9 100644
--- a/app/main/views/new_password.py
+++ b/app/main/views/new_password.py
@@ -1,5 +1,4 @@
 import json
-from datetime import datetime
 
 from flask import (
     current_app,
@@ -29,8 +28,7 @@ def new_password(token):
 
     email_address = json.loads(token_data)['email']
     user = User.from_email_address(email_address)
-    if user.password_changed_at and datetime.strptime(user.password_changed_at, '%Y-%m-%d %H:%M:%S.%f') > \
-            datetime.strptime(json.loads(token_data)['created_at'], '%Y-%m-%d %H:%M:%S.%f'):
+    if user.password_changed_more_recently_than(json.loads(token_data)['created_at']):
         flash('The link in the email has already been used')
         return redirect(url_for('main.index'))
 
diff --git a/app/main/views/service_settings.py b/app/main/views/service_settings.py
index 79447ebe5..707d92a3b 100644
--- a/app/main/views/service_settings.py
+++ b/app/main/views/service_settings.py
@@ -14,6 +14,7 @@ from flask import (
 )
 from flask_login import current_user
 from notifications_python_client.errors import HTTPError
+from notifications_utils.timezones import utc_string_to_aware_gmt_datetime
 
 from app import (
     billing_api_client,
@@ -475,8 +476,10 @@ def get_service_verify_reply_to_address_partials(service_id, notification_id):
                     email_address=notification["to"],
                     is_default=is_default
                 )
-    created_at_no_tz = notification["created_at"][:-6]
-    seconds_since_sending = (datetime.utcnow() - datetime.strptime(created_at_no_tz, '%Y-%m-%dT%H:%M:%S.%f')).seconds
+    seconds_since_sending = (
+        utc_string_to_aware_gmt_datetime(datetime.utcnow().isoformat()) -
+        utc_string_to_aware_gmt_datetime(notification['created_at'])
+    ).seconds
     if notification["status"] in FAILURE_STATUSES or (
         notification["status"] in SENDING_STATUSES and
         seconds_since_sending > current_app.config['REPLY_TO_EMAIL_ADDRESS_VALIDATION_TIMEOUT']
diff --git a/app/models/job.py b/app/models/job.py
index 76ca7d2f1..ecb72dd95 100644
--- a/app/models/job.py
+++ b/app/models/job.py
@@ -5,6 +5,10 @@ from notifications_utils.letter_timings import (
     get_letter_timings,
     letter_can_be_cancelled,
 )
+from notifications_utils.timezones import (
+    local_timezone,
+    utc_string_to_aware_gmt_datetime,
+)
 from werkzeug.utils import cached_property
 
 from app.models import JSONModel, ModelList
@@ -23,6 +27,7 @@ class Job(JSONModel):
         'template_version',
         'original_file_name',
         'created_at',
+        'processing_started',
         'notification_count',
         'job_status',
         'created_by',
@@ -52,7 +57,7 @@ class Job(JSONModel):
     def processing_started(self):
         if not self._dict.get('processing_started'):
             return None
-        return datetime.strptime(self._dict['processing_started'][:-6], '%Y-%m-%dT%H:%M:%S')
+        return utc_string_to_aware_gmt_datetime(self._dict['processing_started'])
 
     def _aggregate_statistics(self, *statuses):
         return sum(
@@ -109,7 +114,7 @@ class Job(JSONModel):
             # notifications yet
             return True
         return (
-            datetime.utcnow() - self.processing_started
+            datetime.utcnow().astimezone(local_timezone) - self.processing_started
         ).days < 1
 
     @property
@@ -142,7 +147,8 @@ class Job(JSONModel):
             return False
 
         if not letter_can_be_cancelled(
-            'created', datetime.strptime(self.created_at[:-6], '%Y-%m-%dT%H:%M:%S.%f')
+            'created',
+            utc_string_to_aware_gmt_datetime(self.created_at).replace(tzinfo=None)
         ):
             return False
 
diff --git a/app/models/user.py b/app/models/user.py
index 61674ce30..ac465000a 100644
--- a/app/models/user.py
+++ b/app/models/user.py
@@ -1,6 +1,7 @@
 from flask import abort, current_app, request, session
 from flask_login import AnonymousUserMixin, UserMixin, login_user
 from notifications_python_client.errors import HTTPError
+from notifications_utils.timezones import utc_string_to_aware_gmt_datetime
 from werkzeug.utils import cached_property
 
 from app.models import JSONModel, ModelList
@@ -108,6 +109,15 @@ class User(JSONModel, UserMixin):
         response = user_api_client.update_password(self.id, password)
         self.__init__(response)
 
+    def password_changed_more_recently_than(self, datetime_string):
+        if not self.password_changed_at:
+            return False
+        return utc_string_to_aware_gmt_datetime(
+            self.password_changed_at
+        ) > utc_string_to_aware_gmt_datetime(
+            datetime_string
+        )
+
     def set_permissions(self, service_id, permissions, folder_permissions):
         user_api_client.set_user_permissions(
             self.id,