Scheduled posts to a specific page

This is what i’m trying to do

I have a gym, and I have some clients who I program workouts for via e-mail every day and some once a week. They don’t come in, they do the work outs at their own gym. I’m trying to create a password protected page they can log in to (I know you can do this with the built in visibility option). I want to pre-setup posts that will display on their set scheduled date/time to that page so rather than e-mail them each day or e-mail them the full week of work outs, they could view the page each day and see the new work out posted.

Please please please help me!!