Added inline date view mode for event instances

config/install/core.entity_view_display.eventinstance.inline_date.yml

+langcode: en
+status: true
+dependencies:
+  enforced:
+    module:
+      - recurring_events
+  config:
+    - core.entity_view_mode.eventinstance.inline_date
+  module:
+    - recurring_events
+id: eventinstace.inline_date
+targetEntityType: eventinstance
+bundle: eventinstance
+mode: inline_date
+content:
+  date:
+    weight: 0
+    label: above
+    settings:
+      separator: '-'
+      format_type: medium
+      timezone_override: ''
+    third_party_settings: {  }
+    type: daterange_default
+hidden:
+  body: true

config/install/core.entity_view_mode.eventinstance.inline_date.yml

+langcode: en
+status: false
+dependencies:
+  enforced:
+    module:
+      - recurring_events
+  module:
+    - recurring_events
+id: eventinstance.inline_date
+label: 'Inline date'
+targetEntityType: eventinstance
+cache: true

recurring_events.routing.yml

+# Event Series.
+
 # View an EventSeries.
 entity.eventseries.canonical:
   path: '/events/series/{eventseries}'
@@ -5,6 +7,10 @@ entity.eventseries.canonical:
     _entity_view: 'eventseries'
   requirements:
     _entity_access: 'eventseries.view'
+  options:
+    parameters:
+      eventseries:
+        type: entity:eventseries
 
 # Add an EventSeries.
 entity.eventseries.add_form:
@@ -67,6 +73,21 @@ entity.eventseries.collection:
   # Checks for permission directly.
     _permission: 'access eventseries overview'
 
+
+# Event Instances.
+
+# View an EventInstance.
+entity.eventinstance.canonical:
+  path: '/events/{eventinstance}'
+  defaults:
+    _entity_view: 'eventinstance'
+  requirements:
+    _entity_access: 'eventinstance.view'
+  options:
+    parameters:
+      eventinstance:
+        type: entity:eventinstance
+
 # Admin Menu Strucutre.
 events.admin.overview:
   path: '/admin/structure/events'

src/Entity/EventSeries.php

@@ -327,6 +327,10 @@ class EventSeries extends EditorialContentEntityBase implements EventInterface {
         'type' => 'string_textfield',
         'weight' => -6,
       ])
+      ->setDisplayOptions('view', [
+        'label' => 'above',
+        'weight' => 10,
+      ])
       ->setDisplayConfigurable('form', TRUE)
       ->setDisplayConfigurable('view', TRUE)
       ->setRevisionable(TRUE)
@@ -343,6 +347,10 @@ class EventSeries extends EditorialContentEntityBase implements EventInterface {
         'type' => 'text_textarea',
         'weight' => -4,
       ])
+      ->setDisplayOptions('view', [
+        'label' => 'above',
+        'weight' => 10,
+      ])
       ->setDisplayConfigurable('form', TRUE);
 
     $fields['recur_type'] = BaseFieldDefinition::create('list_string')
@@ -369,7 +377,11 @@ class EventSeries extends EditorialContentEntityBase implements EventInterface {
           ],
         ],
         'weight' => 1,
-      ]);
+      ])
+      ->setDisplayOptions('view', [
+        'label' => 'above',
+        'weight' => 10,
+      ]);;
 
     $fields['weekly_recurring_date'] = BaseFieldDefinition::create('weekly_recurring_date')
       ->setLabel(t('Weekly Recurring Date'))
@@ -421,8 +433,12 @@ class EventSeries extends EditorialContentEntityBase implements EventInterface {
       ->setSetting('target_type', 'eventinstance')
       ->setTranslatable(FALSE)
       ->setDisplayOptions('view', [
+        'type' => 'entity_reference_entity_view',
         'label' => 'above',
         'weight' => 10,
+        'settings' => [
+          'view_mode' => 'inline_date',
+        ],
       ])
       ->setDisplayConfigurable('view', TRUE)
       ->setDisplayConfigurable('form', FALSE)