Calander in c

I am planning to make a calendar using the C language. Basically, there will be 3-4 main functions for instance the date, month, and year are needed to define the day that corresponds to a particular date. You may make a list of any month's days and dates in any year. The months can be navigated with the arrow keys, or certain other keys can be used to display the next and past months, respectively.
use C language only but also try to add some features like if the user wants to mark or label a specific date and is able to add color to that specific date. and add events.

***need a ppt for demonstrating this