models: Add request_timestamp field to ScheduledMessage table.

This just records the time when the user created the
request to schedule a message or set a reminder.

This would be unused but is future-proofing against a world
where we decide to edit the strings or UI to show when you
asked for the thing.

zerver/lib/export.py

@@ -339,7 +339,7 @@ DATE_FIELDS: dict[TableName, list[Field]] = {
         "date_deleted",
     ],
     "zerver_savedsnippet": ["date_created"],
-    "zerver_scheduledmessage": ["scheduled_timestamp"],
+    "zerver_scheduledmessage": ["scheduled_timestamp", "request_timestamp"],
     "zerver_stream": ["date_created"],
     "zerver_namedusergroup": ["date_created"],
     "zerver_useractivityinterval": ["start", "end"],

zerver/migrations/0698_scheduledmessage_request_timestamp.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.1.8 on 2025-04-24 05:47
+
+import django.utils.timezone
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("zerver", "0697_empty_topic_name_for_dms_from_third_party_imports"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="scheduledmessage",
+            name="request_timestamp",
+            field=models.DateTimeField(default=django.utils.timezone.now),
+        ),
+    ]

zerver/models/scheduled_jobs.py

@@ -152,6 +152,7 @@ class ScheduledMessage(models.Model):
     delivered = models.BooleanField(default=False)
     delivered_message = models.ForeignKey(Message, null=True, on_delete=CASCADE)
     has_attachment = models.BooleanField(default=False, db_index=True)
+    request_timestamp = models.DateTimeField(default=timezone_now)
 
     # Metadata for messages that failed to send when their scheduled
     # moment arrived.