diff --git a/js/src/components/Participation/ParticipationWithoutAccount.vue b/js/src/components/Participation/ParticipationWithoutAccount.vue
index 3337c51e0..ae26b2e65 100644
--- a/js/src/components/Participation/ParticipationWithoutAccount.vue
+++ b/js/src/components/Participation/ParticipationWithoutAccount.vue
@@ -200,6 +200,7 @@ export default class ParticipationWithoutAccount extends Vue {
           email: this.anonymousParticipation.email,
           message: this.anonymousParticipation.message,
           locale: this.$i18n.locale,
+          timezone: Intl.DateTimeFormat().resolvedOptions().timeZone,
         },
         update: (
           store: ApolloCache<{ joinEvent: IParticipant }>,
diff --git a/js/src/graphql/event.ts b/js/src/graphql/event.ts
index 4e9a8baba..8be02ff0c 100644
--- a/js/src/graphql/event.ts
+++ b/js/src/graphql/event.ts
@@ -380,6 +380,7 @@ export const JOIN_EVENT = gql`
     $email: String
     $message: String
     $locale: String
+    $timezone: String
   ) {
     joinEvent(
       eventId: $eventId
@@ -387,6 +388,7 @@ export const JOIN_EVENT = gql`
       email: $email
       message: $message
       locale: $locale
+      timezone: $timezone
     ) {
       ...ParticipantQuery
     }
diff --git a/lib/graphql/schema/events/participant.ex b/lib/graphql/schema/events/participant.ex
index 34093014e..d34d1c64a 100644
--- a/lib/graphql/schema/events/participant.ex
+++ b/lib/graphql/schema/events/participant.ex
@@ -91,6 +91,7 @@ defmodule Mobilizon.GraphQL.Schema.Events.ParticipantType do
       arg(:email, :string, description: "The anonymous participant's email")
       arg(:message, :string, description: "The anonymous participant's message")
       arg(:locale, :string, description: "The anonymous participant's locale")
+      arg(:timezone, :string, description: "The anonymous participant's timezone")
 
       resolve(&Participant.actor_join_event/3)
     end
diff --git a/lib/mobilizon/events/participant_metadata.ex b/lib/mobilizon/events/participant_metadata.ex
index 279575f9b..8b002d095 100644
--- a/lib/mobilizon/events/participant_metadata.ex
+++ b/lib/mobilizon/events/participant_metadata.ex
@@ -15,7 +15,7 @@ defmodule Mobilizon.Events.Participant.Metadata do
           locale: String.t()
         }
 
-  @attrs [:email, :confirmation_token, :cancellation_token, :message, :locale]
+  @attrs [:email, :confirmation_token, :cancellation_token, :message, :locale, :timezone]
 
   @derive Jason.Encoder
   embedded_schema do
@@ -24,6 +24,7 @@ defmodule Mobilizon.Events.Participant.Metadata do
     field(:cancellation_token, :string)
     field(:message, :string)
     field(:locale, :string)
+    field(:timezone, :string)
   end
 
   @doc false
diff --git a/lib/web/email/event.ex b/lib/web/email/event.ex
index 120f1d577..dd0a0b1c5 100644
--- a/lib/web/email/event.ex
+++ b/lib/web/email/event.ex
@@ -14,15 +14,24 @@ defmodule Mobilizon.Web.Email.Event do
   alias Mobilizon.Events.{Event, Participant}
   alias Mobilizon.Storage.Repo
   alias Mobilizon.Users.{Setting, User}
-
   alias Mobilizon.Web.Email
+  alias Mobilizon.Web.JsonLD.ObjectView
 
   @important_changes [:title, :begins_on, :ends_on, :status, :physical_address]
 
-  @spec event_updated(String.t(), Actor.t(), Event.t(), Event.t(), MapSet.t(), String.t()) ::
+  @spec event_updated(
+          Participant.t(),
+          String.t(),
+          Actor.t(),
+          Event.t(),
+          Event.t(),
+          MapSet.t(),
+          String.t()
+        ) ::
           Bamboo.Email.t()
   def event_updated(
         email,
+        %Participant{} = participant,
         %Actor{} = actor,
         %Event{} = old_event,
         %Event{} = event,
@@ -83,13 +92,14 @@ defmodule Mobilizon.Web.Email.Event do
           MapSet.t()
         ) :: Bamboo.Email.t()
   defp send_notification_for_event_update_to_participant(
-         {%Participant{} = _participant, %Actor{} = actor,
+         {%Participant{} = participant, %Actor{} = actor,
           %User{locale: locale, email: email} = _user, %Setting{timezone: timezone}},
          %Event{} = old_event,
          %Event{} = event,
          diff
        ) do
     do_send_notification_for_event_update_to_participant(
+      participant,
       email,
       actor,
       old_event,
@@ -101,13 +111,14 @@ defmodule Mobilizon.Web.Email.Event do
   end
 
   defp send_notification_for_event_update_to_participant(
-         {%Participant{} = _participant, %Actor{} = actor,
+         {%Participant{} = participant, %Actor{} = actor,
           %User{locale: locale, email: email} = _user, nil},
          %Event{} = old_event,
          %Event{} = event,
          diff
        ) do
     do_send_notification_for_event_update_to_participant(
+      participant,
       email,
       actor,
       old_event,
@@ -119,7 +130,8 @@ defmodule Mobilizon.Web.Email.Event do
   end
 
   defp send_notification_for_event_update_to_participant(
-         {%Participant{metadata: %{email: email}} = _participant, %Actor{} = actor, nil, nil},
+         {%Participant{metadata: %{email: email} = participant_metadata} = participant,
+          %Actor{} = actor, nil, nil},
          %Event{} = old_event,
          %Event{} = event,
          diff
@@ -128,17 +140,19 @@ defmodule Mobilizon.Web.Email.Event do
     locale = Gettext.get_locale()
 
     do_send_notification_for_event_update_to_participant(
+      participant,
       email,
       actor,
       old_event,
       event,
       diff,
-      "Etc/UTC",
+      Map.get(participant_metadata, :timezone, "Etc/UTC"),
       locale
     )
   end
 
   @spec do_send_notification_for_event_update_to_participant(
+          Participant.t(),
           String.t(),
           Actor.t(),
           Event.t(),
@@ -148,6 +162,7 @@ defmodule Mobilizon.Web.Email.Event do
           String.t()
         ) :: Bamboo.Email.t()
   defp do_send_notification_for_event_update_to_participant(
+         participant,
          email,
          actor,
          old_event,
@@ -157,7 +172,7 @@ defmodule Mobilizon.Web.Email.Event do
          locale
        ) do
     email
-    |> Email.Event.event_updated(actor, old_event, event, diff, timezone, locale)
+    |> Email.Event.event_updated(participant, actor, old_event, event, diff, timezone, locale)
     |> Email.Mailer.send_email_later()
   end
 end
diff --git a/lib/web/email/participation.ex b/lib/web/email/participation.ex
index 7fea008fb..c363c1a9e 100644
--- a/lib/web/email/participation.ex
+++ b/lib/web/email/participation.ex
@@ -59,7 +59,7 @@ defmodule Mobilizon.Web.Email.Participation do
 
   def participation_updated(
         email,
-        %Participant{event: event, role: :rejected},
+        %Participant{event: event, role: :rejected} = participant,
         locale
       ) do
     Gettext.put_locale(locale)
@@ -73,13 +73,15 @@ defmodule Mobilizon.Web.Email.Participation do
     Email.base_email(to: email, subject: subject)
     |> assign(:locale, locale)
     |> assign(:event, event)
+    |> assign(:jsonLDMetadata, json_ld(participant))
     |> assign(:subject, subject)
     |> render(:event_participation_rejected)
   end
 
   def participation_updated(
         email,
-        %Participant{event: %Event{join_options: :free} = event, role: :participant},
+        %Participant{event: %Event{join_options: :free} = event, role: :participant} =
+          participant,
         locale
       ) do
     Gettext.put_locale(locale)
@@ -94,12 +96,13 @@ defmodule Mobilizon.Web.Email.Participation do
     |> assign(:locale, locale)
     |> assign(:event, event)
     |> assign(:subject, subject)
+    |> assign(:jsonLDMetadata, json_ld(participant))
     |> render(:event_participation_confirmed)
   end
 
   def participation_updated(
         email,
-        %Participant{event: event, role: :participant},
+        %Participant{event: event, role: :participant} = participant,
         locale
       ) do
     Gettext.put_locale(locale)
diff --git a/test/graphql/resolvers/event_test.exs b/test/graphql/resolvers/event_test.exs
index b426ea8ea..6ec807077 100644
--- a/test/graphql/resolvers/event_test.exs
+++ b/test/graphql/resolvers/event_test.exs
@@ -932,11 +932,11 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
 
     test "update_event/3 updates an event", %{conn: conn, actor: actor, user: user} do
       event = insert(:event, organizer_actor: actor)
-      _creator = insert(:participant, event: event, actor: actor, role: :creator)
+      creator = insert(:participant, event: event, actor: actor, role: :creator)
       participant_user = insert(:user)
       participant_actor = insert(:actor, user: participant_user)
 
-      _participant =
+      participant =
         insert(:participant, event: event, actor: participant_actor, role: :participant)
 
       address = insert(:address)
@@ -1009,6 +1009,7 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
 
       assert_delivered_email(
         Email.Event.event_updated(
+          creator,
           user.email,
           actor,
           event,
@@ -1019,6 +1020,7 @@ defmodule Mobilizon.Web.Resolvers.EventTest do
 
       assert_delivered_email(
         Email.Event.event_updated(
+          participant,
           participant_user.email,
           participant_actor,
           event,