title: Show only specific days on calendar
body: <p>I want to know if it's possible to show only specific days in a calendar. I mean, for example, I know that I can create a dialog box with a calendar using:</p>
  
  <p>dialog --title "Test" --calendar "Date:" 0 0 </p>
  
  <p>And it shows every day on the specific months and so on.</p>
  
  <p>But I want to know if I can show only the days like 5, 10, 15, 20, 25, 30 in the same dialog box, but I don't know how to do it or if it can be done that way using that dialog option.</p>