Program Calendar

Hi, so I wanted to push my workout day today to tomorrow, so I went to "Change what day you want to begin" and change it to the next day, didn't do anything to "Move to" and looked at my revised calendar, saw that I moved today's exercise over, but all my other work out days disappeared. I am confused why there are two areas to change your workouts, so a bit confused and sad my other workouts disappeared. Hopefully you can tell me what I did wrong, so I don't this mistake again. Thanks