diff --git a/app/components/rs_auth_details_modal_component.html.erb b/app/components/rs_auth_details_modal_component.html.erb
index 2462dc6..9c0c15f 100644
--- a/app/components/rs_auth_details_modal_component.html.erb
+++ b/app/components/rs_auth_details_modal_component.html.erb
@@ -18,16 +18,19 @@
   </h5>
   <ul class="divide-y divide-gray-100 rounded-lg border border-gray-200" data-turbo-prefetch="false">
     <% @authorizations.each do |auth| %>
-      <li id="<%= rs_device_dom_id(auth) %>" class="flex items-center justify-between gap-4 px-4 py-3">
+      <li id="<%= rs_device_dom_id(auth) %>" class="flex items-center justify-between gap-6 px-4 py-3">
         <div class="min-w-0">
           <p class="mb-1 truncate text-base font-medium"><%= auth.device_label %></p>
           <p class="truncate text-xs text-gray-500">
-            <%= tag.span "Connected #{auth.created_at.strftime('%-d %b %Y')}",
-                  title: connected_at_title(auth) %>
+            Connected <%= timestamp_tag(auth.created_at, title: connected_at_title(auth)) %>
             <span class="mx-1">&middot;</span>
-            <%= tag.span status_label(auth),
-                  title: (expires_at_title(auth) if auth.expire_at.present?),
-                  class: ("text-red-700" if auth.expired?) %>
+            <%= tag.span class: ("text-red-700" if auth.expired?) do %>
+              <% if auth.expire_at.present? %>
+                <%= expiry_prefix(auth) %> <%= timestamp_tag(auth.expire_at, title: expires_at_title(auth)) %>
+              <% else %>
+                Never expires
+              <% end %>
+            <% end %>
           </p>
         </div>
         <%= button_to "Revoke access", services_storage_rs_auth_path(auth), method: :delete,
diff --git a/app/components/rs_auth_details_modal_component.rb b/app/components/rs_auth_details_modal_component.rb
index be140d1..90aef7f 100644
--- a/app/components/rs_auth_details_modal_component.rb
+++ b/app/components/rs_auth_details_modal_component.rb
@@ -9,13 +9,15 @@ class RsAuthDetailsModalComponent < ViewComponent::Base
     @web_app = @auth.web_app
   end
 
-  def status_label(auth)
-    return "Never expires" if auth.expire_at.blank?
-    return "Expired on #{auth.expire_at.strftime('%-d %b %Y')}" if auth.expired?
+  # "Expires" / "Expired on", or nothing when there is no expiry to describe.
+  def expiry_prefix(auth)
+    return nil if auth.expire_at.blank?
 
-    "Expires #{auth.expire_at.strftime('%-d %b %Y')}"
+    auth.expired? ? "Expired on" : "Expires"
   end
 
+  # Fallbacks for the hover titles, used when JavaScript is unavailable.
+  # app/javascript/local_time.js replaces them with the reader's own zone.
   def connected_at_title(auth)
     auth.created_at.strftime("%-d %b %Y, %H:%M")
   end
@@ -23,4 +25,10 @@ class RsAuthDetailsModalComponent < ViewComponent::Base
   def expires_at_title(auth)
     auth.expire_at.strftime("%-d %b %Y, %H:%M")
   end
+
+  # A <time> element carrying the absolute (UTC) timestamp, so the reader's own
+  # local time can be shown alongside the date.
+  def timestamp_tag(time, title:)
+    tag.time time.strftime("%-d %b %Y"), datetime: time.utc.iso8601, title: title
+  end
 end
\ No newline at end of file
diff --git a/app/javascript/application.js b/app/javascript/application.js
index 1e2d3dc..0d92962 100644
--- a/app/javascript/application.js
+++ b/app/javascript/application.js
@@ -1,4 +1,5 @@
 // Configure your import map in config/importmap.rb. Read more: https://github.com/rails/importmap-rails
 import "@hotwired/turbo-rails"
 import "controllers"
-import "turbo_stream_animations"
\ No newline at end of file
+import "turbo_stream_animations"
+import "local_time"
\ No newline at end of file
diff --git a/app/javascript/local_time.js b/app/javascript/local_time.js
new file mode 100644
index 0000000..5f75065
--- /dev/null
+++ b/app/javascript/local_time.js
@@ -0,0 +1,32 @@
+// Timestamps are rendered by the server in UTC, next to a <time> element's
+// machine-readable value. Rewrite those elements' hover titles so they show the
+// reader's own local time instead.
+
+const LOCAL_TIME_FORMAT = new Intl.DateTimeFormat("en-GB", {
+  day: "numeric",
+  month: "short",
+  year: "numeric",
+  hour: "2-digit",
+  minute: "2-digit",
+  hourCycle: "h23",
+})
+
+// Only absolute timestamps carry a zone to convert from: a date-only value would
+// be read as UTC midnight and shift to the previous day for most readers.
+const ABSOLUTE_TIMESTAMP = /T\d{2}:\d{2}(:\d{2})?(\.\d+)?(Z|[+-]\d{2}:\d{2})$/
+
+const localizeTimestamps = () => {
+  document.querySelectorAll("time[datetime]").forEach((element) => {
+    const value = element.getAttribute("datetime")
+
+    if (!ABSOLUTE_TIMESTAMP.test(value)) return
+
+    const timestamp = new Date(value)
+
+    if (!Number.isNaN(timestamp.getTime())) {
+      element.title = LOCAL_TIME_FORMAT.format(timestamp)
+    }
+  })
+}
+
+document.addEventListener("turbo:load", localizeTimestamps)
\ No newline at end of file
diff --git a/config/importmap.rb b/config/importmap.rb
index 692f89b..495f9f2 100644
--- a/config/importmap.rb
+++ b/config/importmap.rb
@@ -5,5 +5,6 @@ pin "@hotwired/turbo-rails", to: "turbo.min.js", preload: true
 pin "@hotwired/stimulus", to: "stimulus.min.js", preload: true
 pin "@hotwired/stimulus-loading", to: "stimulus-loading.js", preload: true
 pin "turbo_stream_animations"
+pin "local_time"
 pin_all_from "app/javascript/controllers", under: "controllers"
 pin "tailwindcss-stimulus-components" # @4.0.3
diff --git a/spec/features/services/rs_auths_spec.rb b/spec/features/services/rs_auths_spec.rb
index a8b8bc7..edb2f20 100644
--- a/spec/features/services/rs_auths_spec.rb
+++ b/spec/features/services/rs_auths_spec.rb
@@ -84,6 +84,18 @@ RSpec.describe "Storage connected apps", type: :feature do
         "li##{ActionView::RecordIdentifier.dom_id(auth, :device)}", visible: false
       )
     end
+
+    it "marks the device timestamps with machine-readable UTC times" do
+      visit apps_services_storage_path
+
+      timestamps = page.all("time[datetime]", visible: false)
+                       .map { |element| Time.iso8601(element["datetime"]) }
+
+      expect(timestamps).to contain_exactly(
+        be_within(1.second).of(auth.created_at),
+        be_within(1.second).of(auth.expire_at)
+      )
+    end
   end
 
   context "with multiple apps" do