Scheduler Module

Hello, after a user responds, I’d like to schedule a message with a delay. I did some digging and found some documentation in the 10.x version for the scheduler module. However, I noticed that in the current version, 12.1.3, the scheduler module is prepended with a . which means that the module isn’t being included. It looks like the module was removed for the 11.x release. So, I have a couple questions. Just out of curiosity, why was the module removed? The more important question is, how can I schedule a message for delivery at some point in the future?