Add cast-timestamp field flag to system tables (#13429)

api/src/database/system-data/fields/activity.yaml

@@ -37,6 +37,9 @@ fields:
 
   - field: timestamp
     display: datetime
+    special:
+      - date-created
+      - cast-timestamp
     options:
       relative: true
     width: half

api/src/database/system-data/fields/dashboards.yaml

@@ -8,7 +8,9 @@ fields:
   - field: panels
     special: o2m
   - field: date_created
-    special: date-created
+    special:
+      - date-created
+      - cast-timestamp
   - field: user_created
     special: user-created
   - field: note

api/src/database/system-data/fields/notifications.yaml

@@ -3,7 +3,9 @@ table: directus_notifications
 fields:
   - field: id
   - field: timestamp
-    special: date-created
+    special:
+      - date-created
+      - cast-timestamp
   - field: status
   - field: recipient
   - field: sender

api/src/database/system-data/fields/panels.yaml

@@ -17,7 +17,9 @@ fields:
   - field: options
     special: cast-json
   - field: date_created
-    special: date-created
+    special:
+      - date-created
+      - cast-timestamp
   - field: user_created
     special: user-created
   - field: dashboard

api/src/database/system-data/fields/shares.yaml

@@ -51,7 +51,9 @@ fields:
     readonly: true
 
   - field: date_created
-    special: date-created
+    special:
+      - date-created
+      - cast-timestamp
     width: half
     readonly: true
     conditions: