It'd help if you said what happens in your example.

What's the task type?

Is it a single device or multiple, individual devices or a group?  If > 1 device, have you just tried it on a single device?  Are there other tasks running at the same time as this task?  

Do you get an error?  If so, what is it?  

Try this:

Task / New Task / Pick task type you want to run

The task form will render.

Fill out the details:

Applies to - you can do this for a group OR you can individually specify the list

Schedule Date - When do you want this to run?  

     Let's say you want it to start running tomorrow at 7:00 AM

2024-02-29 07:00

Task Priority - 3 is the default, if you want this to run ahead of other scheduled tasks that are set to a priority of 3, set it to 1, if you want it to not get in the way, set it to 5

Expand Scheduling Options

Select Daily

Save Task

Fast forward to tomorrow......

That task will run (or try to run) each day at 7:00 AM starting tomorrow.  

Why won't it run?

    There are many possible reasons, you'd need to look at the task results and go from there.

Why isn't it running at 7:00 AM?  It runs at 7:30 or 8, but not at 7....and you want it to run at 7

    Look at the task history and you will probably see other tasks in the queue that are keeping this task from running.  

    Or, let's say you can run 50 tasks at a time and you have scheduled 500 devices to run at 7:00 AM - sorry, 450 devices are not going to be able to run at 7:00.  You've got a few options, all outside of this question, but add more NA cores and increase / improve your core performance (tuning).  Do not do this until you are 100% certain you don't have other issues.