Something in the future has already been fixed
All of these three structures are used to say that something in the future HAS ALREADY BEEN FIXED OR DECIDED (by people and sometimes by nature):
1) Present Simple: 'The sun RISES at 6.18 tomorrow'.
'The train from Birmingham ARRIVES at 8.50'.
'On Tuesday next, the Prime Minister RETURNS to London'.
2) Future Progressive: 'Professor Galbraith WILL BE LECTURING on economics at the same time
'I'LL BE GOING past the shops this afternoon, shall I pick up your shopping
3) To Be + Infinitive: 'The Queen IS TO VISIT France next year'.
'There IS TO BE a strike on March 26th'.
Are there any differences between these structures, WHEN THEY HAVE THE MEANING STATED ABOVE?
If yes, what are they?