what happens if you pass too few arguments into a function in c code example

Example: too few arguments to function in c

// "error: too few arguments to function 'printDay'" means you're passing
// the wrong number of argument to printDay when you call it here:
printDay(input());
// You're passing one argument but your declaration of printDay shows 
// that it takes 3 arguments:
void printDay(int month, int day, int firstDay);