The simple present for future?

I did search on the internet. but I couldn't still understand well how to use simple present for future. every grammar book says "simple present is used for events in the future which are 'timetabled, scheduled"

1. 
   
   

   What does here timetable / schedule mean?

   
   


2. 
   

   What is the difference between present simple (when used for future) and present continuous (when used for future)?

   
   

   For example, Difference between the sentence

   
   

   
   

   The sun rises at 6.00 tomorrow

   
   

   
   

   and

   
   

   
   
   

   The sun is rising at 6.00 tomorrow