The count_time won't update when you put all the codes
in a single loop, it just keep waiting....

It should work if you put the if statement to another function
since the engine can handle multiple processes at the same time.

Code:

---

function check_count_time()
{
   if(count_time > 1816)
   {
      wait(-5);
      bronze_pan.visible = on;
      set_mouse(2);
   } 
}

function Year_startup() //calculates year
{
   while(count_time >= 0)
   {
	wait(week);
	wait(week);
	wait(week);
	wait(week);  
        // bTW, why not write : wait(week*4);

	count_time += 1;
		
	check_count_time();
	wait(1); 
  }
} 

---