Using Siri Shortcuts for Automated Messaging and Alarms

Great. Here is how to create the personal automation:

1. Open Shortcuts on your iPhone.
2. Tap Automations in the bottom toolbar.
3. Tap "+" (upper right).
4. Choose "Alarm" in the list of triggers.
5. Choose "Goes Off".
6. On the same page, choose "Existing".
7. Select your alarm(s) and tap Done (upper right).
8. Choose "Run Immediately".
9. Tap Next (top right).
10. Choose "New Blank Automation" (the gray rectangle).
11. In the search bar, search for "send message" and tap the result to add the action.
12. Tap the "Message" field and enter the message you want to send.
13. Tap "Recipients" to choose the people you want to send the message to. Add as many people as you want and tap Done (upper right).
14. Tap Done (upper right).

To make sure the automation works to your liking, consider using only your own phone number in the "Recipients" for testing (that's what I do.) If everything works, edit the automation to choose the right people.

I put out a call for some of the Shortcut experts here in the forums. Hopefully, they will stop by.

If not, try posting in a currently active thread about Shortcuts asking for help in this thread (include the link to this thread). As long as you're brief and don't try to get your question answered in that thread, it's not considered threadjacking.

You would need to use a Personal Automation in the Shortcuts app.

There are 2 things you can do: either send a message at a specific time everyday, or send a message based on an alarm going off in the Clock application.

Which option would you prefer?

Note that there is also a way to schedule messages without using Shortcuts, if that’s what you are seeking: Schedule a message on iPhone to send later - Apple Support.

The shortcut you are referring to (the one provided in the last answer) is to create alarms in the Clock app, based on the input time. Given a time, it creates 8 alarms: 3 alarms 5, 10 and 15 minutes before the input time and 5 alarms at 1 minute intervals after the input time. I don't know the purpose of settings so many alarms but the user probably had very good reasons to do so.

Now, the shortcut is not for sending a message. All it does is to set up alarms.

Unfortunately, the personal automation solution indicated above will not work in the situation where you create alarms on the fly. The personal automation needs to be created based on an existing, repeating daily alarm.

Could you give us more information on what you are trying to achieve? We may be able to offer different means of achieving it.

You can start here:

Shortcuts User Guide - Apple Support

Also, searching the internet for "Siri shortcuts to send someone a message based on an alarm automatically at a certain time" might net you an example you can work from.