Those categories are just command buttons. Add as many as you want and modify code as appropriate. Will have to resize and/or move things around to make more buttons fit. I probably would have designed with a combobox or listbox instead of buttons for categories.
Ooops, I just looked at the Daily calendar. This shows categories as columns. Now I see why developer limited to 10 categories. Expanding may not be practical with this app. How many more?
To include category info for weekly calendar, I modified one line of code in ShowWeekAppts procedure:
Code:
vString = RichTextCode(vSubject & "; Cat " & rst!CategoryID & String(45, " "), rst!CatColor, vbBlack, False, False) 'format text with back color
added: & "; Cat " & rst!CategoryID