How can I create a shortcut that will announce the time every 30 minutes?

Could someone kindly assist me in creating a simple shortcut that will announce the time every 30 minutes from 9:00 AM to 8:00 PM on my phone, as if I were explaining it to a 10-year-old? I mention this because I have never successfully set up a shortcut before due to its perceived complexity. Despite spending countless hours watching instructional videos and attempting to create and execute one, I have consistently encountered difficulties. 

my iMac automatically announces the time every 30 minutes at my office, but the iMac has a setting that automatically does it. I wish that the iPhone had this same setting integrated. I have been unsuccessful at trying to create a successful shortcut for it, for the past couple of years now.

I would be FOREVER grateful!

THANK YOU!!

[Re-Titled by Moderator]