diff --git a/Gemfile b/Gemfile
index 2dd779838..4295eb57e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'rails', '6.1.7.6'
+gem 'rails', '7.0.8'
 # This needs to be in here for Heroku
 ruby '3.0.6'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 60ab5b6a7..0d334b672 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -19,71 +19,77 @@ GIT
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (6.1.7.6)
-      actionpack (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    actioncable (7.0.8)
+      actionpack (= 7.0.8)
+      activesupport (= 7.0.8)
       nio4r (~> 2.0)
       websocket-driver (>= 0.6.1)
-    actionmailbox (6.1.7.6)
-      actionpack (= 6.1.7.6)
-      activejob (= 6.1.7.6)
-      activerecord (= 6.1.7.6)
-      activestorage (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    actionmailbox (7.0.8)
+      actionpack (= 7.0.8)
+      activejob (= 7.0.8)
+      activerecord (= 7.0.8)
+      activestorage (= 7.0.8)
+      activesupport (= 7.0.8)
       mail (>= 2.7.1)
-    actionmailer (6.1.7.6)
-      actionpack (= 6.1.7.6)
-      actionview (= 6.1.7.6)
-      activejob (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+      net-imap
+      net-pop
+      net-smtp
+    actionmailer (7.0.8)
+      actionpack (= 7.0.8)
+      actionview (= 7.0.8)
+      activejob (= 7.0.8)
+      activesupport (= 7.0.8)
       mail (~> 2.5, >= 2.5.4)
+      net-imap
+      net-pop
+      net-smtp
       rails-dom-testing (~> 2.0)
-    actionpack (6.1.7.6)
-      actionview (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
-      rack (~> 2.0, >= 2.0.9)
+    actionpack (7.0.8)
+      actionview (= 7.0.8)
+      activesupport (= 7.0.8)
+      rack (~> 2.0, >= 2.2.4)
       rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.2.0)
-    actiontext (6.1.7.6)
-      actionpack (= 6.1.7.6)
-      activerecord (= 6.1.7.6)
-      activestorage (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    actiontext (7.0.8)
+      actionpack (= 7.0.8)
+      activerecord (= 7.0.8)
+      activestorage (= 7.0.8)
+      activesupport (= 7.0.8)
+      globalid (>= 0.6.0)
       nokogiri (>= 1.8.5)
-    actionview (6.1.7.6)
-      activesupport (= 6.1.7.6)
+    actionview (7.0.8)
+      activesupport (= 7.0.8)
       builder (~> 3.1)
       erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.1, >= 1.2.0)
-    activejob (6.1.7.6)
-      activesupport (= 6.1.7.6)
+    activejob (7.0.8)
+      activesupport (= 7.0.8)
       globalid (>= 0.3.6)
-    activemodel (6.1.7.6)
-      activesupport (= 6.1.7.6)
+    activemodel (7.0.8)
+      activesupport (= 7.0.8)
     activemodel-serializers-xml (1.0.2)
       activemodel (> 5.x)
       activesupport (> 5.x)
       builder (~> 3.1)
-    activerecord (6.1.7.6)
-      activemodel (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    activerecord (7.0.8)
+      activemodel (= 7.0.8)
+      activesupport (= 7.0.8)
     activerecord-safer_migrations (3.0.0)
       activerecord (>= 5.2)
-    activestorage (6.1.7.6)
-      actionpack (= 6.1.7.6)
-      activejob (= 6.1.7.6)
-      activerecord (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    activestorage (7.0.8)
+      actionpack (= 7.0.8)
+      activejob (= 7.0.8)
+      activerecord (= 7.0.8)
+      activesupport (= 7.0.8)
       marcel (~> 1.0)
       mini_mime (>= 1.1.0)
-    activesupport (6.1.7.6)
+    activesupport (7.0.8)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
       tzinfo (~> 2.0)
-      zeitwerk (~> 2.3)
     addressable (2.8.5)
       public_suffix (>= 2.0.2, < 6.0)
     ast (2.4.2)
@@ -322,21 +328,20 @@ GEM
       rack (~> 2.2, >= 2.2.4)
     rack-test (2.1.0)
       rack (>= 1.3)
-    rails (6.1.7.6)
-      actioncable (= 6.1.7.6)
-      actionmailbox (= 6.1.7.6)
-      actionmailer (= 6.1.7.6)
-      actionpack (= 6.1.7.6)
-      actiontext (= 6.1.7.6)
-      actionview (= 6.1.7.6)
-      activejob (= 6.1.7.6)
-      activemodel (= 6.1.7.6)
-      activerecord (= 6.1.7.6)
-      activestorage (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    rails (7.0.8)
+      actioncable (= 7.0.8)
+      actionmailbox (= 7.0.8)
+      actionmailer (= 7.0.8)
+      actionpack (= 7.0.8)
+      actiontext (= 7.0.8)
+      actionview (= 7.0.8)
+      activejob (= 7.0.8)
+      activemodel (= 7.0.8)
+      activerecord (= 7.0.8)
+      activestorage (= 7.0.8)
+      activesupport (= 7.0.8)
       bundler (>= 1.15.0)
-      railties (= 6.1.7.6)
-      sprockets-rails (>= 2.0.0)
+      railties (= 7.0.8)
     rails-controller-testing (1.0.5)
       actionpack (>= 5.0.1.rc1)
       actionview (>= 5.0.1.rc1)
@@ -348,12 +353,13 @@ GEM
     rails-html-sanitizer (1.6.0)
       loofah (~> 2.21)
       nokogiri (~> 1.14)
-    railties (6.1.7.6)
-      actionpack (= 6.1.7.6)
-      activesupport (= 6.1.7.6)
+    railties (7.0.8)
+      actionpack (= 7.0.8)
+      activesupport (= 7.0.8)
       method_source
       rake (>= 12.2)
       thor (~> 1.0)
+      zeitwerk (~> 2.5)
     rainbow (3.1.1)
     rake (13.1.0)
     rb-fsevent (0.11.2)
@@ -572,7 +578,7 @@ DEPENDENCIES
   pvb-instrumentation!
   rack (>= 2.1.4)
   rack-canonical-host
-  rails (= 6.1.7.6)
+  rails (= 7.0.8)
   rails-controller-testing
   rake
   request_store
diff --git a/app/decorators/nomis/contact_decorator.rb b/app/decorators/nomis/contact_decorator.rb
index 6ee405377..c29e0a653 100644
--- a/app/decorators/nomis/contact_decorator.rb
+++ b/app/decorators/nomis/contact_decorator.rb
@@ -4,7 +4,7 @@ class Nomis::ContactDecorator < Draper::Decorator
   def full_name_and_dob
     [
       "#{given_name} #{surname}",
-      date_of_birth&.to_s(:short_nomis)
+      date_of_birth&.to_fs(:short_nomis)
     ].compact.join(' - ')
   end
 
diff --git a/app/decorators/rejection_decorator.rb b/app/decorators/rejection_decorator.rb
index c6da70c2e..514d3988b 100644
--- a/app/decorators/rejection_decorator.rb
+++ b/app/decorators/rejection_decorator.rb
@@ -50,7 +50,7 @@ def email_visitor_banned_explanation(visitor)
     if visitor.banned_until?
       h.t('visitor_banned_until_html',
           name: visitor.anonymized_name.titleize,
-          banned_until: visitor.banned_until.to_s(:short_nomis),
+          banned_until: visitor.banned_until.to_fs(:short_nomis),
           scope: %i[visitor_mailer rejected])
     else
       h.t('visitor_banned_html',
diff --git a/app/helpers/date_helper.rb b/app/helpers/date_helper.rb
index 790b84072..047c18103 100644
--- a/app/helpers/date_helper.rb
+++ b/app/helpers/date_helper.rb
@@ -1,6 +1,6 @@
 module DateHelper
   def format_date(datetime)
-    datetime.to_date.to_s(:short_abbrev)
+    datetime.to_date.to_fs(:short_abbrev)
   end
 
   def format_date_of_birth(datetime)
@@ -45,7 +45,7 @@ def format_slot_for_public(slot)
   def format_slot_for_staff(slot)
     I18n.t(
       'formats.slot.staff',
-      date: slot.begin_at.to_date.to_s(:full_nomis),
+      date: slot.begin_at.to_date.to_fs(:full_nomis),
       begin: format_time_24hr(slot.begin_at),
       end: format_time_24hr(slot.end_at)
     )
@@ -53,7 +53,7 @@ def format_slot_for_staff(slot)
 
   def format_visit_slot_date_for_staff(visit)
     slot = visit.slot_granted || visit.slots.first
-    slot.to_date.to_s(:short_nomis)
+    slot.to_date.to_fs(:short_nomis)
   end
 
   def format_visit_slot_times_for_staff(visit)
diff --git a/app/services/estate_visit_query.rb b/app/services/estate_visit_query.rb
index ddfd13cb6..94db7641b 100644
--- a/app/services/estate_visit_query.rb
+++ b/app/services/estate_visit_query.rb
@@ -8,7 +8,7 @@ def visits_to_print_by_slot(date)
 
     visits = Visit.includes(:prisoner, :visitors, :prison)
              .processed.from_estates(@estates)
-             .where('slot_granted LIKE ?', "#{date.to_s(:db)}%")
+             .where('slot_granted LIKE ?', "#{date.to_fs(:db)}%")
              .order('slot_granted asc').to_a
 
     grouped_visits(visits)
diff --git a/app/services/nomis/oauth/client.rb b/app/services/nomis/oauth/client.rb
index e5a2ffb07..8582ac56f 100644
--- a/app/services/nomis/oauth/client.rb
+++ b/app/services/nomis/oauth/client.rb
@@ -3,6 +3,11 @@
 module Nomis
   module Oauth
     class Client
+      class_attribute :nomis_oauth_client_id, :nomis_oauth_client_secret
+
+      self.nomis_oauth_client_id     = Rails.configuration.nomis_oauth_client_id
+      self.nomis_oauth_client_secret = Rails.configuration.nomis_oauth_client_secret
+
       def initialize(host)
         @host = host
         @connection = Faraday.new
@@ -34,9 +39,7 @@ def authorisation
       end
 
       def credentials
-        Base64.strict_encode64(
-          "#{Rails.configuration.nomis_oauth_client_id}:#{Rails.configuration.nomis_oauth_client_secret}"
-        )
+        Base64.strict_encode64("#{nomis_oauth_client_id}:#{nomis_oauth_client_secret}")
       end
     end
   end
diff --git a/app/services/nomis/oauth/jwks_service.rb b/app/services/nomis/oauth/jwks_service.rb
index 074844bdf..9f980a751 100644
--- a/app/services/nomis/oauth/jwks_service.rb
+++ b/app/services/nomis/oauth/jwks_service.rb
@@ -5,12 +5,14 @@ module Oauth
     class JwksService
       include Singleton
 
-      HOST = Rails.configuration.nomis_oauth_host
+      class_attribute :host
+
+      self.host = Rails.configuration.nomis_oauth_host
 
       attr_reader :oauth_client
 
       def initialize(oauth_client: Nomis::Oauth::Client)
-        @oauth_client = oauth_client.new(HOST)
+        @oauth_client = oauth_client.new(host)
       end
 
       def fetch_keys
diff --git a/app/services/nomis/oauth/token_service.rb b/app/services/nomis/oauth/token_service.rb
index 6acf23322..3bfaf0cdb 100644
--- a/app/services/nomis/oauth/token_service.rb
+++ b/app/services/nomis/oauth/token_service.rb
@@ -5,6 +5,10 @@ module Oauth
     class TokenService
       include Singleton
 
+      class_attribute :host
+
+      self.host = Rails.configuration.nomis_oauth_host
+
       class << self
         delegate :valid_token, to: :instance
       end
@@ -25,9 +29,7 @@ def token
       end
 
       def fetch_token
-        host = Rails.configuration.nomis_oauth_host
         oauth_client = Nomis::Oauth::Client.new(host)
-
         route = '/auth/oauth/token?grant_type=client_credentials'
         response = oauth_client.post(route)
         Token.from_json(response)
diff --git a/app/views/prison/dashboards/_cancellations.html.erb b/app/views/prison/dashboards/_cancellations.html.erb
index ad650de79..049dce84e 100644
--- a/app/views/prison/dashboards/_cancellations.html.erb
+++ b/app/views/prison/dashboards/_cancellations.html.erb
@@ -20,10 +20,10 @@
         <tr>
           <td aria-label="<%= t('prisoner_number', scope: :shared) %>"><%= visit.prisoner_number %></td>
           <td class="long" aria-label="<%= t('prisoner_name', scope: :shared) %>"><%= visit.prisoner_full_name %></td>
-          <td class="long" aria-label="<%= t('dob', scope: :shared) %>"><%= visit.prisoner_date_of_birth.to_s(:short_nomis) %></td>
+          <td class="long" aria-label="<%= t('dob', scope: :shared) %>"><%= visit.prisoner_date_of_birth.to_fs(:short_nomis) %></td>
           <td aria-label="<%= t('visit_date', scope: :shared) %>"><%= format_visit_slot_date_for_staff(visit) %></td>
           <td aria-label="<%= t('time_slot', scope: :shared) %>"><%= format_visit_slot_times_for_staff(visit) %></td>
-          <td aria-label="<%= t('cancelled', scope: :shared) %>"><%= visit.cancellation.created_at.to_s(:short) %></td>
+          <td aria-label="<%= t('cancelled', scope: :shared) %>"><%= visit.cancellation.created_at.to_fs(:short) %></td>
           <td aria-label="<%= t('prison', scope: :shared) %>"><%= visit.prison_name %></td>
           <td aria-label="<%= t('reference_number', scope: :shared) %>"><%= visit.reference_no %></td>
           <td aria-label="<%= t('actions', scope: :shared) %>">
diff --git a/app/views/prison/dashboards/_inbox_results.html.erb b/app/views/prison/dashboards/_inbox_results.html.erb
index d5ca9cd23..f51d17566 100644
--- a/app/views/prison/dashboards/_inbox_results.html.erb
+++ b/app/views/prison/dashboards/_inbox_results.html.erb
@@ -1,10 +1,10 @@
 <% @requested_visits.group_by {|v| v.created_at.to_date}.each do |date, booking| %>
   <h3 class="bold-medium">
     <span class="text-secondary font-small"><%= t('requested_on', scope: :shared) %></span>
-    <%= date.to_s(:short) %>
+    <%= date.to_fs(:short) %>
   </h3>
   <table class="table--hover push-bottom push-top--half tablesorter">
-    <caption class="visuallyhidden"><%= t('title', scope: [:prison, :dashboards, :inbox]).capitalize %> - <%= t('requested_on', scope: :shared).downcase %><%= date.to_s(:short) %></caption>
+    <caption class="visuallyhidden"><%= t('title', scope: [:prison, :dashboards, :inbox]).capitalize %> - <%= t('requested_on', scope: :shared).downcase %><%= date.to_fs(:short) %></caption>
     <thead>
       <tr>
         <th scope="col" data-sorter="false"><%= t('prisoner_name', scope: :shared) %></th>
diff --git a/app/views/prison/dashboards/_inbox_search_results.html.erb b/app/views/prison/dashboards/_inbox_search_results.html.erb
index cba09af3c..597a93275 100644
--- a/app/views/prison/dashboards/_inbox_search_results.html.erb
+++ b/app/views/prison/dashboards/_inbox_search_results.html.erb
@@ -14,9 +14,9 @@
     <% visits.each do |visit| %>
       <tr>
         <td class="long" aria-label="<%= t('prisoner_name', scope: :shared) %>"><%= visit.prisoner_full_name %></td>
-        <td aria-label="<%= t('visit_date', scope: :shared) %>"><%= visit.slots.first.to_date.to_s(:short_nomis) %></td>
+        <td aria-label="<%= t('visit_date', scope: :shared) %>"><%= visit.slots.first.to_date.to_fs(:short_nomis) %></td>
         <td aria-label="<%= t('visitor_name', scope: :shared) %>"><%= visit.principal_visitor.full_name %></td>
-        <td aria-label="<%= t('requested', scope: :shared) %>"><%= visit.created_at.to_s(:short) %></td>
+        <td aria-label="<%= t('requested', scope: :shared) %>"><%= visit.created_at.to_fs(:short) %></td>
         <td aria-label="<%= t('prison', scope: :shared) %>"><%= visit.prison_name %></td>
         <td aria-label="<%= t('actions', scope: :shared) %>">
           <%= link_to prison_visit_path(visit), title: t('view', scope: :shared) do %>
diff --git a/app/views/prison/dashboards/_print_cancelled_slot.html.erb b/app/views/prison/dashboards/_print_cancelled_slot.html.erb
index 0272e6ae4..be8642b9f 100644
--- a/app/views/prison/dashboards/_print_cancelled_slot.html.erb
+++ b/app/views/prison/dashboards/_print_cancelled_slot.html.erb
@@ -16,17 +16,17 @@
       <tr>
         <td><%= visit.prisoner_full_name %></td>
         <td><%= visit.prisoner_number %></td>
-        <td><%= visit.principal_visitor.full_name %><br>(<%= visit.principal_visitor.date_of_birth.to_s(:short_nomis) %>)</td>
+        <td><%= visit.principal_visitor.full_name %><br>(<%= visit.principal_visitor.date_of_birth.to_fs(:short_nomis) %>)</td>
         <td><%= visit.contact_phone_no %></td>
         <td>
           <div>
             <% visit.visitors[1..-1].each do |visitor| %>
-              <%= visitor.full_name %> (<%= visitor.date_of_birth.to_s(:short_nomis) %>)<br>
+              <%= visitor.full_name %> (<%= visitor.date_of_birth.to_fs(:short_nomis) %>)<br>
             <% end %>
           </div>
         </td>
         <td><%= visit.prison_name %></td>
-        <td><%= visit.updated_at.to_s(:short) %></td>
+        <td><%= visit.updated_at.to_fs(:short) %></td>
       </tr>
     <% end %>
   </tbody>
diff --git a/app/views/prison/dashboards/_print_slot.html.erb b/app/views/prison/dashboards/_print_slot.html.erb
index 8fd96e7dc..394f4a5f9 100644
--- a/app/views/prison/dashboards/_print_slot.html.erb
+++ b/app/views/prison/dashboards/_print_slot.html.erb
@@ -20,7 +20,7 @@
       <tr>
         <td aria-label="<%= t('prisoner_name', scope: :shared) %>"><%= visit.prisoner_full_name %></td>
         <td aria-label="<%= t('prisoner_number', scope: :shared) %>"><%= visit.prisoner_number %></td>
-        <td aria-label="<%= t('lead_visitor', scope: :shared) %>"><%= visit.principal_visitor.full_name %><br>(<%= visit.principal_visitor.date_of_birth.to_s(:short_nomis) %>)</td>
+        <td aria-label="<%= t('lead_visitor', scope: :shared) %>"><%= visit.principal_visitor.full_name %><br>(<%= visit.principal_visitor.date_of_birth.to_fs(:short_nomis) %>)</td>
         <td aria-label="<%= t('tel', scope: :shared) %>"><%= visit.contact_phone_no %></td>
         <td aria-label="<%= t('additional_visitors', scope: :shared) %>">
           <div>
diff --git a/app/views/prison/dashboards/_request_summary_row.html.erb b/app/views/prison/dashboards/_request_summary_row.html.erb
index 7bdf64035..424c63ff7 100644
--- a/app/views/prison/dashboards/_request_summary_row.html.erb
+++ b/app/views/prison/dashboards/_request_summary_row.html.erb
@@ -1,8 +1,8 @@
 <tr>
   <td class="long" aria-label="<%= t('prisoner_name', scope: :shared) %>"><%= visit.prisoner_full_name %></td>
-  <td aria-label="<%= t('visit_date', scope: :shared) %>" sorttable_customkey="<%= visit.slots.first %>"><%= visit.slots.first.to_date.to_s(:short_nomis) %></td>
+  <td aria-label="<%= t('visit_date', scope: :shared) %>" sorttable_customkey="<%= visit.slots.first %>"><%= visit.slots.first.to_date.to_fs(:short_nomis) %></td>
   <td aria-label="<%= t('visitor_name', scope: :shared) %>"><%= visit.principal_visitor.full_name %></td>
-  <td aria-label="<%= t('requested', scope: :shared) %>"><%= visit.created_at.to_s(:time) %></td>
+  <td aria-label="<%= t('requested', scope: :shared) %>"><%= visit.created_at.to_fs(:time) %></td>
   <td aria-label="<%= t('prison', scope: :shared) %>"><%= visit.prison_name %></td>
   <td aria-label="<%= t('actions', scope: :shared) %>">
     <%= link_to prison_visit_path(visit), {:title => t('view', scope: :shared)} do %>
diff --git a/app/views/prison/print_visits/show.html.erb b/app/views/prison/print_visits/show.html.erb
index dc98309da..d704e076c 100644
--- a/app/views/prison/print_visits/show.html.erb
+++ b/app/views/prison/print_visits/show.html.erb
@@ -19,7 +19,7 @@
 <% end -%>
 
 <% if !@submitted_date.nil? && !@data.any? %>
-  <p class="lede"><%= t('.no_visits', date: @submitted_date.to_s(:short_nomis)) %></p>
+  <p class="lede"><%= t('.no_visits', date: @submitted_date.to_fs(:short_nomis)) %></p>
 <% end -%>
 
 <% if @submitted_date.nil? %>
diff --git a/app/views/prison/visits/_prisoner_details.html.erb b/app/views/prison/visits/_prisoner_details.html.erb
index 906d32a17..df0da9c9a 100644
--- a/app/views/prison/visits/_prisoner_details.html.erb
+++ b/app/views/prison/visits/_prisoner_details.html.erb
@@ -32,7 +32,7 @@
 
   <div class="column-one-quarter">
     <span class="text-secondary"><%= t('.prisoner_dob') %></span>
-    <div class="bold-small"><%= @visit.prisoner_date_of_birth.to_s(:short_nomis) %></div>
+    <div class="bold-small"><%= @visit.prisoner_date_of_birth.to_fs(:short_nomis) %></div>
     <% case @visit.prisoner_existance_status %>
     <% when PrisonerDetailsPresenter::VALID, PrisonerLocationValidation::INVALID %>
       <div class="tag tag--booked font-xsmall"><%= t('.verified') %></div>
diff --git a/app/views/prison/visits/_processed.html.erb b/app/views/prison/visits/_processed.html.erb
index 041d0fd68..6351995b4 100644
--- a/app/views/prison/visits/_processed.html.erb
+++ b/app/views/prison/visits/_processed.html.erb
@@ -6,10 +6,10 @@
     <div class="column-two-thirds">
       <div class="grid-row">
         <div class="column-one-third">
-          <div class="tag tag--requested tag--heading"><%= t('requested', scope: 'shared') %>: <br><%= @visit.created_at.to_date.to_s(:short_nomis) %> - <%= @visit.created_at.to_s(:time) %></div>
+          <div class="tag tag--requested tag--heading"><%= t('requested', scope: 'shared') %>: <br><%= @visit.created_at.to_date.to_fs(:short_nomis) %> - <%= @visit.created_at.to_fs(:time) %></div>
         </div>
         <div class="column-one-third">
-          <div class="tag tag--<%= @visit.processing_state %> tag--heading"><%= @visit.processing_state.capitalize %>: <br><%= @visit.processed_at.to_date.to_s(:short_nomis) %> - <%= @visit.processed_at.to_s(:time) %></div>
+          <div class="tag tag--<%= @visit.processing_state %> tag--heading"><%= @visit.processing_state.capitalize %>: <br><%= @visit.processed_at.to_date.to_fs(:short_nomis) %> - <%= @visit.processed_at.to_fs(:time) %></div>
         </div>
         <div class="column-one-third">
           <div class="text-secondary">ID: <%= @visit.human_id %></div>
diff --git a/app/views/prison/visits/_processed_prisoner_details.html.erb b/app/views/prison/visits/_processed_prisoner_details.html.erb
index 4e342df7a..3254723e0 100644
--- a/app/views/prison/visits/_processed_prisoner_details.html.erb
+++ b/app/views/prison/visits/_processed_prisoner_details.html.erb
@@ -9,7 +9,7 @@
 
   <div class="column-one-quarter">
     <span class="text-secondary"><%= t('prisoner_dob', scope: %i[prison visits prisoner_details]) %></span>
-    <div class="bold-small"><%= @visit.prisoner_date_of_birth.to_s(:short_nomis) %></div>
+    <div class="bold-small"><%= @visit.prisoner_date_of_birth.to_fs(:short_nomis) %></div>
   </div>
 
   <div class="column-one-quarter">
diff --git a/app/views/prison/visits/_requested.html.erb b/app/views/prison/visits/_requested.html.erb
index 8889ac68f..368917042 100644
--- a/app/views/prison/visits/_requested.html.erb
+++ b/app/views/prison/visits/_requested.html.erb
@@ -23,7 +23,7 @@
     <div class="column-one-half">
       <div class="grid-row">
         <div class="column-two-thirds">
-          <div class="tag tag--requested tag--heading"><%= t('requested', scope: 'shared') %>: <br><%= @visit.created_at.to_date.to_s(:short_nomis) %> - <%= @visit.created_at.to_s(:time) %></div>
+          <div class="tag tag--requested tag--heading"><%= t('requested', scope: 'shared') %>: <br><%= @visit.created_at.to_date.to_fs(:short_nomis) %> - <%= @visit.created_at.to_fs(:time) %></div>
         </div>
       </div>
     </div>
diff --git a/app/views/prison/visits/_timeline.html.erb b/app/views/prison/visits/_timeline.html.erb
index 1ce165dc4..2bf6032cb 100644
--- a/app/views/prison/visits/_timeline.html.erb
+++ b/app/views/prison/visits/_timeline.html.erb
@@ -2,7 +2,7 @@
   <ul>
     <% VisitTimeline.new(@visit).events.each do |event| %>
       <%= content_tag :li, class: timeline_event_html_class(event) do -%>
-        <div class="timeline__date"><%= event.created_at.to_s(:timeline_date) %><span class="timeline__smalltext"><%= event.created_at.to_s(:timeline_time) %></span></div>
+        <div class="timeline__date"><%= event.created_at.to_fs(:timeline_date) %><span class="timeline__smalltext"><%= event.created_at.to_fs(:timeline_time) %></span></div>
         <div class="timeline__status"><%= t(".#{event.state}") %><span class="timeline__smalltext"><%= t('.by', name: event.user_name || t('.anonymous')) %></span></div>
       <% end -%>
     <% end -%>
diff --git a/app/views/prison/visits/_visitor_contact.html.erb b/app/views/prison/visits/_visitor_contact.html.erb
index d086a4532..1e9ccc932 100644
--- a/app/views/prison/visits/_visitor_contact.html.erb
+++ b/app/views/prison/visits/_visitor_contact.html.erb
@@ -11,7 +11,7 @@
     <div class="column">
       <div class="name">
         <%= vf.hidden_field :id %>
-        <span class="bold-small"><%= v.full_name %></span> - <%= v.date_of_birth.to_s(:short_nomis) %>
+        <span class="bold-small"><%= v.full_name %></span> - <%= v.date_of_birth.to_fs(:short_nomis) %>
         <span class="font-small">(<%= v.age %>)</span>
       </div>
       <% if @visit.principal_visitor == v %>
diff --git a/app/views/prison/visits/_visitor_detail.html.erb b/app/views/prison/visits/_visitor_detail.html.erb
index 1e97ec10d..a58b56e3d 100644
--- a/app/views/prison/visits/_visitor_detail.html.erb
+++ b/app/views/prison/visits/_visitor_detail.html.erb
@@ -11,7 +11,7 @@
             <span class="tag tag--rejected font-xsmall text-center">
               <%= t('.rejected_banned') %>
               <% if @visit.principal_visitor.banned_until? %>
-                <%= t('.until') %> <%= @visit.principal_visitor.banned_until.to_date.to_s(:short_nomis) %>
+                <%= t('.until') %> <%= @visit.principal_visitor.banned_until.to_date.to_fs(:short_nomis) %>
               <% end %>
             </span>
           <% elsif @visit.principal_visitor.not_on_list %>
@@ -39,7 +39,7 @@
         <div class="column-one-quarter">
           <dl>
             <dt><%= t('.dob') %></dt>
-            <dd><%= @visit.principal_visitor.date_of_birth.to_s(:short_nomis) %> (<%= @visit.principal_visitor.age %>)</dd>
+            <dd><%= @visit.principal_visitor.date_of_birth.to_fs(:short_nomis) %> (<%= @visit.principal_visitor.age %>)</dd>
           </dl>
         </div>
         <div class="column-one-quarter">
diff --git a/app/views/visitor_mailer/booked.html.erb b/app/views/visitor_mailer/booked.html.erb
index f434c6836..30671eaa1 100644
--- a/app/views/visitor_mailer/booked.html.erb
+++ b/app/views/visitor_mailer/booked.html.erb
@@ -41,7 +41,7 @@
   <% @visit.banned_visitors.each do |v| %>
     <p>
       <% if v.banned_until? %>
-        <%= t('.visitor_banned_until_html', name: v.anonymized_name, banned_until: v.banned_until.to_s(:short_nomis)) %>
+        <%= t('.visitor_banned_until_html', name: v.anonymized_name, banned_until: v.banned_until.to_fs(:short_nomis)) %>
       <% else %>
         <%= t('.visitor_banned_html', name: v.anonymized_name) %>
       <% end %>
diff --git a/bin/rake b/bin/rake
index 7327f471e..4fbf10b96 100755
--- a/bin/rake
+++ b/bin/rake
@@ -1,5 +1,4 @@
 #!/usr/bin/env ruby
-load File.expand_path("spring", __dir__)
 require_relative "../config/boot"
 require "rake"
 Rake.application.run
diff --git a/bin/setup b/bin/setup
index 90700ac4f..8f0cfddbc 100755
--- a/bin/setup
+++ b/bin/setup
@@ -1,5 +1,5 @@
 #!/usr/bin/env ruby
-require "fileutils"
+require 'fileutils'
 
 # path to your application root.
 APP_ROOT = File.expand_path('..', __dir__)
@@ -20,17 +20,17 @@ FileUtils.chdir APP_ROOT do
   # Install JavaScript dependencies
   system! 'bin/yarn'
 
-  # puts "\n== Copying sample files =="
+  # puts '\n== Copying sample files =='
   # unless File.exist?('config/database.yml')
   #   FileUtils.cp 'config/database.yml.sample', 'config/database.yml'
   # end
 
-  puts "\n== Preparing database =="
+  puts '\n== Preparing database =='
   system! 'bin/rails db:prepare'
 
-  puts "\n== Removing old logs and tempfiles =="
+  puts '\n== Removing old logs and tempfiles =='
   system! 'bin/rails log:clear tmp:clear'
 
-  puts "\n== Restarting application server =="
+  puts '\n== Restarting application server =='
   system! 'bin/rails restart'
 end
diff --git a/config/application.rb b/config/application.rb
index 0cfd67375..5e81d06ef 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -15,6 +15,7 @@
 require 'sprockets/railtie'
 require 'rails/test_unit/railtie'
 require_relative '../app/middleware/http_method_not_allowed'
+require_relative '../app/middleware/robots_tag'
 
 # Require the gems listed in Gemfile, including any gems
 # you've limited to :test, :development, or :production.
@@ -24,6 +25,7 @@ module PrisonVisits
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 6.1
+
     config.autoload_paths += %w[app/metrics/support]
     config.eager_load_paths += %w[app/metrics/support]
 
@@ -53,6 +55,7 @@ class Application < Rails::Application
     config.sentry_dsn = ENV['SENTRY_DSN']
     config.sentry_js_dsn = ENV['SENTRY_JS_DSN']
 
+    config.middleware.use RobotsTag
     config.middleware.insert_before Rack::Head, HttpMethodNotAllowed
 
     config.sendgrid_api_user = ENV['SMTP_USERNAME']
diff --git a/config/boot.rb b/config/boot.rb
index b9e460cef..30f5120df 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,3 @@
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.
-require 'bootsnap/setup' # Speed up boot time by caching expensive operations.
diff --git a/config/initializers/new_framework_defaults_7_0.rb b/config/initializers/new_framework_defaults_7_0.rb
new file mode 100644
index 000000000..b2fc1683c
--- /dev/null
+++ b/config/initializers/new_framework_defaults_7_0.rb
@@ -0,0 +1,141 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file eases your Rails 7.0 framework defaults upgrade.
+#
+# Uncomment each configuration one by one to switch to the new default.
+# Once your application is ready to run with all new defaults, you can remove
+# this file and set the `config.load_defaults` to `7.0`.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+# https://guides.rubyonrails.org/upgrading_ruby_on_rails.html
+
+# `button_to` view helper will render `<button>` element, regardless of whether
+# or not the content is passed as the first argument or as a block.
+# Rails.application.config.action_view.button_to_generates_button_tag = true
+
+# `stylesheet_link_tag` view helper will not render the media attribute by default.
+# Rails.application.config.action_view.apply_stylesheet_media_default = false
+
+# Change the digest class for the key generators to `OpenSSL::Digest::SHA256`.
+# Changing this default means invalidate all encrypted messages generated by
+# your application and, all the encrypted cookies. Only change this after you
+# rotated all the messages using the key rotator.
+#
+# See upgrading guide for more information on how to build a rotator.
+# https://guides.rubyonrails.org/v7.0/upgrading_ruby_on_rails.html
+# Rails.application.config.active_support.key_generator_hash_digest_class = OpenSSL::Digest::SHA256
+
+# Change the digest class for ActiveSupport::Digest.
+# Changing this default means that for example Etags change and
+# various cache keys leading to cache invalidation.
+# Rails.application.config.active_support.hash_digest_class = OpenSSL::Digest::SHA256
+
+# Don't override ActiveSupport::TimeWithZone.name and use the default Ruby
+# implementation.
+# Rails.application.config.active_support.remove_deprecated_time_with_zone_name = true
+
+# Calls `Rails.application.executor.wrap` around test cases.
+# This makes test cases behave closer to an actual request or job.
+# Several features that are normally disabled in test, such as Active Record query cache
+# and asynchronous queries will then be enabled.
+# Rails.application.config.active_support.executor_around_test_case = true
+
+# Set both the `:open_timeout` and `:read_timeout` values for `:smtp` delivery method.
+# Rails.application.config.action_mailer.smtp_timeout = 5
+
+# The ActiveStorage video previewer will now use scene change detection to generate
+# better preview images (rather than the previous default of using the first frame
+# of the video).
+# Rails.application.config.active_storage.video_preview_arguments =
+#   "-vf 'select=eq(n\\,0)+eq(key\\,1)+gt(scene\\,0.015),loop=loop=-1:size=2,trim=start_frame=1' -frames:v 1 -f image2"
+
+# Automatically infer `inverse_of` for associations with a scope.
+# Rails.application.config.active_record.automatic_scope_inversing = true
+
+# Raise when running tests if fixtures contained foreign key violations
+# Rails.application.config.active_record.verify_foreign_keys_for_fixtures = true
+
+# Disable partial inserts.
+# This default means that all columns will be referenced in INSERT queries
+# regardless of whether they have a default or not.
+# Rails.application.config.active_record.partial_inserts = false
+
+# Protect from open redirect attacks in `redirect_back_or_to` and `redirect_to`.
+# Rails.application.config.action_controller.raise_on_open_redirects = true
+
+# Change the variant processor for Active Storage.
+# Changing this default means updating all places in your code that
+# generate variants to use image processing macros and ruby-vips
+# operations. See the upgrading guide for detail on the changes required.
+# The `:mini_magick` option is not deprecated; it's fine to keep using it.
+# Rails.application.config.active_storage.variant_processor = :vips
+
+# Enable parameter wrapping for JSON.
+# Previously this was set in an initializer. It's fine to keep using that initializer if you've customized it.
+# To disable parameter wrapping entirely, set this config to `false`.
+# Rails.application.config.action_controller.wrap_parameters_by_default = true
+
+# Specifies whether generated namespaced UUIDs follow the RFC 4122 standard for namespace IDs provided as a
+# `String` to `Digest::UUID.uuid_v3` or `Digest::UUID.uuid_v5` method calls.
+#
+# See https://guides.rubyonrails.org/configuring.html#config-active-support-use-rfc4122-namespaced-uuids for
+# more information.
+# Rails.application.config.active_support.use_rfc4122_namespaced_uuids = true
+
+# Change the default headers to disable browsers' flawed legacy XSS protection.
+# Rails.application.config.action_dispatch.default_headers = {
+#   "X-Frame-Options" => "SAMEORIGIN",
+#   "X-XSS-Protection" => "0",
+#   "X-Content-Type-Options" => "nosniff",
+#   "X-Download-Options" => "noopen",
+#   "X-Permitted-Cross-Domain-Policies" => "none",
+#   "Referrer-Policy" => "strict-origin-when-cross-origin"
+# }
+
+# ** Please read carefully, this must be configured in config/application.rb **
+# Change the format of the cache entry.
+# Changing this default means that all new cache entries added to the cache
+# will have a different format that is not supported by Rails 6.1 applications.
+# Only change this value after your application is fully deployed to Rails 7.0
+# and you have no plans to rollback.
+# When you're ready to change format, add this to `config/application.rb` (NOT this file):
+#  config.active_support.cache_format_version = 7.0
+
+# Cookie serializer: 2 options
+#
+# If you're upgrading and haven't set `cookies_serializer` previously, your cookie serializer
+# is `:marshal`. The default for new apps is `:json`.
+#
+# Rails.application.config.action_dispatch.cookies_serializer = :json
+#
+#
+# To migrate an existing application to the `:json` serializer, use the `:hybrid` option.
+#
+# Rails transparently deserializes existing (Marshal-serialized) cookies on read and
+# re-writes them in the JSON format.
+#
+# It is fine to use `:hybrid` long term; you should do that until you're confident *all* your cookies
+# have been converted to JSON. To keep using `:hybrid` long term, move this config to its own
+# initializer or to `config/application.rb`.
+#
+# Rails.application.config.action_dispatch.cookies_serializer = :hybrid
+#
+#
+# If your cookies can't yet be serialized to JSON, keep using `:marshal` for backward-compatibility.
+#
+# If you have configured the serializer elsewhere, you can remove this section of the file.
+#
+# See https://guides.rubyonrails.org/action_controller_overview.html#cookies for more information.
+
+# Change the return value of `ActionDispatch::Request#content_type` to the Content-Type header without modification.
+# Rails.application.config.action_dispatch.return_only_request_media_type_on_content_type = false
+
+# Active Storage `has_many_attached` relationships will default to replacing the current collection instead of appending to it.
+# Thus, to support submitting an empty collection, the `file_field` helper will render an hidden field `include_hidden` by default when `multiple_file_field_include_hidden` is set to `true`.
+# See https://guides.rubyonrails.org/configuring.html#config-active-storage-multiple-file-field-include-hidden for more information.
+# Rails.application.config.active_storage.multiple_file_field_include_hidden = true
+
+# ** Please read carefully, this must be configured in config/application.rb (NOT this file) **
+# Disables the deprecated #to_s override in some Ruby core classes
+# See https://guides.rubyonrails.org/configuring.html#config-active-support-disable-to-s-conversion for more information.
+# config.active_support.disable_to_s_conversion = true
diff --git a/lib/excon/middleware/deadline.rb b/lib/excon/middleware/deadline.rb
index 1f7c72b49..d1bbcf57d 100644
--- a/lib/excon/middleware/deadline.rb
+++ b/lib/excon/middleware/deadline.rb
@@ -10,7 +10,7 @@ def initialize(deadline, exceeded_by)
 
       def message
         "Deadline exceeded by #{@exceeded_by.abs}, \
-expected to have completed by #{@deadline.to_s(:iso8601)}"
+expected to have completed by #{@deadline.to_fs(:iso8601)}"
       end
     end
   end
diff --git a/spec/decorators/nomis/contact_decorator_spec.rb b/spec/decorators/nomis/contact_decorator_spec.rb
index a8c04b695..84f1ab8d1 100644
--- a/spec/decorators/nomis/contact_decorator_spec.rb
+++ b/spec/decorators/nomis/contact_decorator_spec.rb
@@ -9,7 +9,7 @@
     let(:full_name) { "#{contact.given_name} #{contact.surname}" }
 
     context 'with a dob' do
-      it { expect(subject.full_name_and_dob).to eq("#{full_name} - #{contact.date_of_birth.to_s(:short_nomis)}") }
+      it { expect(subject.full_name_and_dob).to eq("#{full_name} - #{contact.date_of_birth.to_fs(:short_nomis)}") }
     end
 
     context 'with no dob' do
diff --git a/spec/features/print_visits_spec.rb b/spec/features/print_visits_spec.rb
index c918fe064..2dae2a6f8 100644
--- a/spec/features/print_visits_spec.rb
+++ b/spec/features/print_visits_spec.rb
@@ -38,7 +38,7 @@
 
       click_button('Show')
 
-      expect(page).to have_css('p', text: "No visits on #{date.to_s(:short_nomis)}")
+      expect(page).to have_css('p', text: "No visits on #{date.to_fs(:short_nomis)}")
     end
 
     context 'when searching for visits' do
@@ -55,7 +55,7 @@
 
         click_button('Show')
 
-        expect(page).to have_css('h3', text: "Visit date #{requested_date.to_s(:short_nomis)}")
+        expect(page).to have_css('h3', text: "Visit date #{requested_date.to_fs(:short_nomis)}")
         expect(page).to have_css('h3', text: 'Visit time 14:00–16:00')
         booked_visits.each do |v|
           expect(page).to have_css('tr td', text: v.prisoner_number)
diff --git a/spec/helpers/date_helper_spec.rb b/spec/helpers/date_helper_spec.rb
index ed75ed4d6..acd21bd42 100644
--- a/spec/helpers/date_helper_spec.rb
+++ b/spec/helpers/date_helper_spec.rb
@@ -72,7 +72,7 @@
       let(:slot_granted) { nil }
 
       it 'formats the preferred slot' do
-        expect(subject).to eq(preferred_slot.to_date.to_s(:short_nomis))
+        expect(subject).to eq(preferred_slot.to_date.to_fs(:short_nomis))
       end
     end
 
@@ -80,7 +80,7 @@
       let(:slot_granted) { ConcreteSlot.new(2015, 11, 5, 13, 30, 14, 45) }
 
       it 'formats the granted slot' do
-        expect(subject).to eq(slot_granted.to_date.to_s(:short_nomis))
+        expect(subject).to eq(slot_granted.to_date.to_fs(:short_nomis))
       end
     end
   end
diff --git a/spec/mailers/visitor_mailer/booked_spec.rb b/spec/mailers/visitor_mailer/booked_spec.rb
index 7763df59c..9cbf43b25 100644
--- a/spec/mailers/visitor_mailer/booked_spec.rb
+++ b/spec/mailers/visitor_mailer/booked_spec.rb
@@ -36,7 +36,7 @@
   end
 
   it 'notifies of the banned visitor' do
-    expect(mail.html_part.body).to match("until #{banned_until.to_s(:short_nomis)}")
+    expect(mail.html_part.body).to match("until #{banned_until.to_fs(:short_nomis)}")
   end
 
   context 'with an acceptance staff message' do
diff --git a/spec/services/nomis/client_spec.rb b/spec/services/nomis/client_spec.rb
index 29024a818..f560bcce7 100644
--- a/spec/services/nomis/client_spec.rb
+++ b/spec/services/nomis/client_spec.rb
@@ -117,20 +117,16 @@
       '7gWVC1gPrm6-S6CoIGu54KNQ6hF8rsntFeFvPr1ff8WrRgOtg'
     end
 
-    let(:config) do
-      {
-        nomis_oauth_host: 'http://localhost:9090',
-        nomis_oauth_client_id: 'test',
-        nomis_oauth_client_secret: '6+9tp<TO4b0!s)>>hSA.Kq7Rjtab.6V9P-lW*TZIW:2nj8>u&2F&>snY5G9v'
-      }
-    end
+    let(:nomis_oauth_host) { 'http://localhost:9090' }
+    let(:nomis_oauth_client_id) { 'test' }
+    let(:nomis_oauth_client_secret) { '6+9tp<TO4b0!s)>>hSA.Kq7Rjtab.6V9P-lW*TZIW:2nj8>u&2F&>snY5G9v' }
 
     before do
-      config.each do |key, val|
-        allow(Rails.configuration).to receive(key).and_return(val)
-      end
+      Nomis::Oauth::TokenService.host = nomis_oauth_host
+      Nomis::Oauth::Client.nomis_oauth_client_id = nomis_oauth_client_id
+      Nomis::Oauth::Client.nomis_oauth_client_secret = nomis_oauth_client_secret
 
-      stub_request(:post, 'http://localhost:9090/auth/oauth/token?grant_type=client_credentials')
+      stub_request(:post, "#{nomis_oauth_host}/auth/oauth/token?grant_type=client_credentials")
         .to_return(
           body: {
             access_token: access_token,
@@ -145,6 +141,12 @@
         )
     end
 
+    after do
+      Nomis::Oauth::TokenService.host = Rails.configuration.nomis_oauth_host
+      Nomis::Oauth::Client.nomis_oauth_client_id = Rails.configuration.nomis_oauth_client_id
+      Nomis::Oauth::Client.nomis_oauth_client_secret = Rails.configuration.nomis_oauth_client_secret
+    end
+
     it 'sends an Authorization header containing a JWT token', vcr: { cassette_name: 'client-auth' } do
       subject.get(path, params)
       expect(WebMock).to have_requested(:get, /\w/)
diff --git a/spec/services/nomis/oauth/client_spec.rb b/spec/services/nomis/oauth/client_spec.rb
index 03f28e339..c882e47ae 100644
--- a/spec/services/nomis/oauth/client_spec.rb
+++ b/spec/services/nomis/oauth/client_spec.rb
@@ -12,8 +12,13 @@
       let(:client_secret) { 'a_value_like_>>>_that_base64_encodes_with_plus_or_slash' }
 
       before do
-        allow(Rails.configuration).to receive(:nomis_oauth_client_id).and_return(client_id)
-        allow(Rails.configuration).to receive(:nomis_oauth_client_secret).and_return(client_secret)
+        described_class.nomis_oauth_client_id = client_id
+        described_class.nomis_oauth_client_secret = client_secret
+      end
+
+      after do
+        described_class.nomis_oauth_client_id = Rails.configuration.nomis_oauth_host
+        described_class.nomis_oauth_client_secret = Rails.configuration.nomis_oauth_client_secret
       end
 
       it 'sets the Authorization header' do